What are officers who resign their commissions and then enlist called?

I know of a very dedicated man who had a long and distinguished career that spanned over 40 years of Active, Guard, and Reserve time.  He enlisted at the age of 17, eventually earned his Commission, rose through the ranks to become a Major, then found that after having commanded men in combat, the years ahead of him as a staff officer just simply did not appeal to him. So, he resigned his Commission, and returned to the ranks as a SSG and climbed the ladder to become a Command Sergeant Major before he finally retired in the early 1990s. This man saw combat in Vietnam as an Officer, and deployed to Desert Storm as the First Sergeant of an MP Company I once commanded years later. The only thing I think can adequately fit a Soldier of this caliber is Patriot.

I checked thoroughly and there is nothing in the official listing of military slang terms. I thought I would share it with the rest of the RP Family - Enjoy:
Latest terms:

Football Bat – An individual or way of doing things that is particularly odd.
Gone Elvis – A service member who is missing in action.
Grid Squares – A non-existent item recruits are typically told to go find.
Helo – Short-hand term for a helicopter.
Jesus Slippers – Military-issued shower footwear.
#
4 Dicks of Death – A Marine nickname for the beef links included with beans in certain MREs. Aptly named for their foul taste and similar appearance to male genetalia.
11 Bullet Catcher/Bang-Bang – An Army infantryman. Recommended by user NGH144.
A
Air Picket – Any airborne system tasked with detecting, reporting, and tracking enemy aerial movements within a certain area of operation.
Alpha Charlie – Military alphabet used to represent ass chewing. Defines getting verbally reprimanded. Recommended by user Joe Trejo.
Anymouse – A lockbox on Navy ships where sailors may drop anonymous suggestions.
Ass – Armored vehicles such as Strykers and Tanks.
Ate-Up – Describes a servicemember who follows regulations so closely that they disregard the context of the situation. Conversely, may describe a servicemember who doesn't understand regulations at all.
B
Band-Aid – A Vietnam-era term for a medic.
Bang-bang – An Army term describing a pistol or rifle.
Big Voice – Term used to describe the loudspeaker on a military base. The Big Voice warns of everything from incoming attacks to scheduled ordnance disposal.
Bird – Slang for helicopter.
Bitchin' Betty – Most U.S. military aircraft feature warning systems that frequently utilize female voices. The phrase is derived from the same anthropmorphizing many apply to GPS units in cars, only Bitchin' Betty's alert pilots to life-threatening situations.
'Black' on ammo, fuel, water, etc. – A common phrase which denotes that a particular resource is gone.
Blowed up – The state of being hit by an IED.
Blue Falcon – A euphemism for buddy **** or buddy ****er, which is slang for a backstabber. Recommended by user jpchopper.
Bolo – A derogatory remark for recruits who cannot pass marksmanship training. The idea being that if one cannot use a rifle, one most resort to a bolo.
Bone – A B-1 bomber.
Bull**** Bomb – A package intended to disperse propaganda leaflets. Recommended by user Steve Neal.
Bullwinkle Badge – Another name for the Air Assault Badge. Recommended by user David E Windsor II.
Burn Bag – A bag used to hold shredded documents, designed to be burned. May also refer to a useless person. Recommended by user Gregory Waugh.
C
Cannibalize – The act of taking workable parts of one item and using them in another.
Chancre Mechanic – Medical officer who checks servicemembers for venereal diseases. Recommended by user jloman42.
Charlie Foxtrot – Commonly used expression utilizing the military alphabet to stand for clusterf***.
Chem-Light Batteries – A mythical object that would be extremely, functionally pointless. Often the source of fruitless hunts embarked upon by hapless privates.Recommended by user Nick_1.
Chicken plates – Sheets of protective material, called Small Arms Protective Inserts, which are used in the Interceptor body armor system.
Comics – Term used to describe maps presented by military intelligence. The term is fairly derogatory in nature as a slight against the accuracy of the maps. It also refers to the brightly colored layouts and symbols usually included.
Commo – Communications equipment or the individuals who operate it. Usually given to Communications Officers on U.S. Navy vessels.
Crank – Navy term for a sailor pulling temporary duty in the galley.
Crumb Catcher – Military slang describing the mouth.
Crusher – Hats worn by pilots during World War II. The hat's wide top brim would need to be crushed down to allow for headsets to be worn.
D
Dear John – Common term referring to a significant other breaking up with a service member through a letter. Recommended by user wilburbythepsea.
Demilitarized Zone – A specific area in which any type of military force including but not limited to personnel, hardware, and infrastructure are banned.
Digit Midget – Usually used with a number as a prefix. X digit midget refers to the number of days till an individual goes on leave or retires. Recommended by user Steve Pinder.
Dittybopper – A term in the Army refering to signals intelligence radio operators trained to utilize Morse Code. Also used as a verb to describe soldiers marching out of synch with a cadence.
Dope on a Rope – Derogatory term used for air-assault Soldiers.
Dustoff – Specifically, a medical evacuation by helicopter.
Dynamited Chicken – Term originating in the Navy referring to either chicken cacciatore or chicken a la king.
E
Embed – When a reporter stays with the military in order to conduct journalistic business. They are typically provided with security and basic necessities provided by the unit they are embedded with.
Expectant – A casualty who is expected to pass away.
F
Fang – A verb to describe being rebuked, called out, or otherwise disparaged.
Fangs – A Marine Corps term for one's teeth.
Fart Sack – Refers to either a sleeping bag or an airman's flight suit.
Farts and Darts – Refers to the clouds and lightning bolt embellishments found on Air Force officer caps. Recommended by user NGH144.
Fashion Show – A Naval punishment where a sailor is required to dress in each of his uniforms over a period of several hours.
Fast Mover – Slang for a Jet Fighter. Aptly named due to the rapidity of a Jet Fighter's movement.
First Light – The time of nautical twilight when the sun is 12 degrees below the horizon.
Flaming ***hole – An Air Force term to describe the fiery effect of a jet plane turning on its afterburners during combat or any other military operation.
Flight Suit Insert – Air Force slang for a pilot.
Fitty – Slang for an M2 .50 caliber machine gun.
Football Bat – An individual or way of doing things that is particularly odd.
Force Projection – The ability of a nation-state to extend military force beyond their borders.
Fourth Point of Contact – From rolling after a successful parachute drop: a term to describe an individual's buttocks. The first three points are feet, calves, and back of the thigh. Recommended by user elisemorgan.
Fruit Salad – Slang for a servicemember's display of medals and ribbons on a dress uniform. Recommended by user DL_in _DEN.
Fugazi – Completely out of whack, ****ed up, screwy. This term originated during the Vietnam War and experienced limited use by civilians.
G
Galloping Dandruff – An Army term used since World War I to refer to crab lice.
Geardo – An Army term for a soldier who spends an inordinate amount of money on gear, regardless of actual need.
Gedunk – Refers to snack foods, such as candy and chips, as well as the place they're sold. Associated with the Navy, and can be used in the phrase "gedunk sailor" as a pejorative remark for inexperienced sailors. Recommended by user bensonmccloud.
Gofasters – A term for sneakers used in the Army, Navy, and Marine Corps.
GOFO – Literally stands for "grasp of the ****ing obvious."
Gone Elvis – A service member who is missing in action.
Grape –A term with two meanings; one for the Air Force and one for the Navy. A Navy Grape is an individual who refuels aircraft. An Air Force Grape, on the other hand, refers to an easy assignment, and can be used as a compliment when a service member makes something look easy.
Great Mistakes – The name Sailors have given the Great Lakes Naval Training Center north of Chicago. It references the closing of two other training facilities in San Diego, California and Orlando, Florida which are both feature far more enjoyable weather.
Grid Squares – A non-existent item recruits are typically told to go find.
Groundhog Day – Term originating from the titular movie which refers to deployments that seem to proceed in the exact same way despite attempts to change them.
Gum Shoe – Navy slang for a Sailor Cryptology Technician. The first CT school was located on top of a building where tar would get stuck to the bottom of students' shoes.
Gun – Term for a mortar or artillery piece. Must never be used within the military to describe a pistol or rifle.
Gunner – A servicemember who operates a crew-served weapon, such as a piece of artillery or ship's cannon. Recommended by user John Alfred.
H
Hangar Queen – An aircraft that is used primarily for spare parts to repair other planes. Recommended by Steve Pinder.
Hardball – A hard-surfaced road.
Hardened Site – A structure usually built under rock or concrete designed to withstand conventional, nuclear, biological, and chemical attack.
Hat Up – To change one's location. Refers to the need to wear a hat for the intended destination. Recommended by user JimBrown1946.
Hawk – Term for cold weather. Commonly referred to as, "the hawk."
Helo – Short-hand term for a helicopter.
High Speed – An individual who his highly motivated and at or near peak efficacy. Can be used sarcastically. Recommended by user sara.
Hit the Silk – Ejecting from an aircraft and utilizing a parachute.
I
Inactive Status – Members of the Reserves who are unable to train for points, receive pay, and cannot be considered for promotion.
Ink Stick – Marine Corps term for a pen.
Iron Rations – Rations used in an emergency survival situation.
J
Jawa – Term for an Army Soldier who is stationed in a desert area, named after the desert-dwelling aliens of "Star Wars."
Jesus Slippers – Military-issued shower footwear.
Jockstrap Medal – Derogatory term for medals given by the military to active CIA members.
Joe – Army term for a soldier. Shortened from G.I. Joe.
Joint Operation Planning – All type of planning involving joint military forces in regards to military operations including, but not limited to, mobilization, deployment, and sustainment.
K
Kinetic – Slang adjective meaning violent.
Klicks – Kilometers.
L
Latrine Queen – Air Force specific term for a trainee in basic who is in charge of the team responsible for cleaning bathrooms.
Left Handed Monkey Wrench – A non-existent tool. Often the object of fruitless searches undertaken by recruits at the behest of more experienced servicemembers. Recommended by user John Alfred.
Long Pig – Slang for when a human being is used as a source of food. Typically this happens in extremely desperate situations.
M
Major Nuclear Power – Any nation-state with a nuclear arsenal capable of being delivered to any other nation in the world.
Meat Identifier – A dish or sauce that identifies what type of meat is being served. For example, cranberry sauce indicates turkey while applesauce indicates pork chops.
Meat Wagon – Slang for an ambulance, or any other medical emergency vehicle.Recommended by user 5712540.
Moonbeam – Marine term for flashlight.
Moving Like Pond Water – Moving so slowly that at unique term is required to describe it. Recommended by user 31320680.
Mustang – Term referring to any officer who was promoted from the enlisted ranks. Can be used respectfully or perjoratively.
N
Nut to Butt – The instruction used to tell Soldiers to line up in tight, forward facing line wherein one's nuts are in extreme proximity to the butt of Soldier before them.
O
Officer's Candy – Navy term used by sailors to describe the scented cake placed in urinals.
Officer of the Deck – Any officer charged with the operation of a ship. Reports to the commanding officer, executive officer, and navigator for relevant issues and concerns.
Over the Hill – Missing in action or someone who has officially gone missing from their post.
Oxygen Thief – A biting piece of slang for someone who's useless or talks too much.
P
Pad Eye Remover – A non-existent item used by sailors to trick new servicemembers into a fruitless search. Pad-eyes are used to secure airplanes with chains.
People Tank – A U.S. Navy term for the inner hull of a submarine.
Pill Pusher – A U.S. Navy term for a hospital corpsman.
Pink Mist – A distinct effect created by certain types of gunshot wounds.
Pogey Bait – Snack food. A "pogue" is an individual who does not serve on the frontlines and performs non-combat oriented roles. "Pogey bait" is, subsequently, a bribe given to these individuals in exchange for expedited or high-quality services.
Pollywog – A sailor who has not crossed the equator on a U.S. Navy ship. Recommended by user Terry Thomason.
Puddle Pirate – Member of the Coast Guard. So called due to a fallacious belief that the Coast Guard never operates in deep water.
PX Ranger – An individual who purchases, from the Post Exchange, paraphernalia unique to certain prestigious ranks or occupations and passes them off as though they earned the items. Recommended by mw1968.
Q
Quay – A man-made structure between a shore and land which can be used by ships to berth and is typically an area for handling cargo.
R
Rainbow – A new recruit in basic training. Recommended by user wilburbythespea.
Red Team – A body of experts on a specific topic who are instructed to research and suggest alternative methods regarding a planned course of action.
Remington Raider – A somewhat derogatory term used for Marines given the harrowing task of performing office duties.
Rocks and Shoals – U.S. Navy rules and regulations.
Rotorhead – Slang for a helicopter pilot. Recommended by user Bob Pante.
Ruck Up – "Ruck" is short for "ruck sack" which refers to backpacks servicemembers sometimes wear. To "ruck up" is to get through a particularly challenging or stressful situation. Recommended by mw1968.
S
Salad Bar – References the service ribbons found on a military uniform.
Scrambled Eggs – Refers to the embellishments found on some officer's caps.Recommended by user NGH144.
Self-Propelled Sandbags – A derogatory term for a Marine based on their emphasis on fighting on the front lines. Recommended by user Nathan King.
Shavetail – A term referring to second lieutenants in the U.S. Army. It primarily refers to the haircuts received in Officer Candidate School. The terms origins date back to the time when the Army used pack animals, and handlers shaved the tale of newly-broken animals to distinguish them from those more seasoned.
Shellback – A sailor who has crossed the equator on a U.S. Navy ship. Responsible for turning all Pollywog's into Shellbacks once they cross the equator themselves. Recommended by user Terry Thomason.
Snake Eater – Member of the U.S. Army Special Forces.
S*** on a Shingle – Slang for a piece of toast with gravy. Recommended by user Mike W.
Sky Blossom – A deployed parachute.
Slick Sleeve – Refers to a sailor who has not yet earned a rank which requires decoration on the sleeves.
Smoke – To punish a servicemember with excessive physical work due to a minor infraction.
Snivel Gear – Any equipment meant for use in cold weather. Recommended by mw1968.
Soap chips – A psychological operations (PSYOPS) tactic where fake letters from an enemy's home country are written and placed on bodies and battle wreckage. They include sentimental content, hint at the infidelity of loved ones back home, and are designed to demoralize combatants.
Soup Sandwich – Used to describe an individual, object, situation, or mission that has gone horribly wrong. The thrust of the term's meaning derives from the fact that it is incredibly difficult, some would say impossible, to make a sandwich out of soup. Recommended by user David E Windsor II.
Swoop – Marine term for a weekend trip off base.
T
Taco – An Air Force term for recieving an "unsatisfactory" grade on a training exercise due to the vague taco-shape of the letter "u."
Tango Uniform – Slang for "tits up," which is the position dead bodies tend to face. The term can be applied to the deceased as well as broken pieces of equipment.Recommended by users 10741875 and iaff.
Target Discrimination – The capability of a surveillance or guidance system to choose certain targets when multiple options are presented.
Trench Monkey – A derogatory term referring to a member of the U.S. Army.
Twidget – A sailor who repairs electronic equipment. Suggested by user X-USN-DS1.
U
Un-Ass – To move immediately or leave one's current position.
Uncle Sam's Canoe Club – A U.S. Navy term for the U.S. Coast Guard.
Unit Identification Code – A an alphanumeric, six-character string which identifies all active, reserve, and guard unit of the United States military.
V
Voice in the Sky – Term referring military base announcements broadcast over speakers. Recommended by user MrsMSgt.
Voluntold – An assignment that is technically voluntary but understood to be mandatory.
W
Weapons of Mass Destruction – Weapons which can cause destruction or death beyond the ability of conventional weapons. These typically are nuclear, biological, chemical, radiological, or high-yield explosive in nature. This definition does not include the vehicle, or transportation method, of delivering the weapon.
Z
Zone of Action – A smaller section of a larger area. Typically these are under the purview of a tactical unit, usually during an offensive maneuver.
Zoomie – Term used by non-flying servicemembers for anyone who operates a flying vehicle.

I know my information is old but, this is what was in the 70s. After vietnam, many officers got eliminated in the force cutbacks. If they had 8 years as an officer, and completed 20 years of service they could retire at the officer grade. Therefore many chose to stay for 20. However, an officer with a regular commission could not assume an NCO grade, even if he/she had held such in the past.

So, I would have had to enlist as an E-3. The drop in pay was too much to force on my family so I got out. After 3 years I enlisted in the Army Reserve and did 8.5 years which allowed me to retire at age 60 as a captain and all of my active duty time 14+ years counted in figuring my pay.

What was I called? I was called a mustang for having gone enlisted to officer while on active duty. I was called Sgt during my reserve time. I was an E-6 and E-7.

And I am sure I was called a few of other select names throughout.