When one is recommended for the Silver Star or the Medal of Honor, the term gallantry in the criteria. How is it different than heroism?

I asked that a long time ago and received this answer.

A Heroism write up will make you go, "Wow."

A Gallantry write up will make you go, "Holy shit!"

When in question, it is useful to do a search for the Etymology -- the study of the origin of words -- and evolution of a term to derive its purpose.

According to the Online Etymology Dictionary, Gallantry:

gallant (adj.)
mid-15c., "showy, finely dressed; gay, merry," from Old French galant "courteous," earlier "amusing, entertaining; lively, bold" (14c.), present participle of galer "rejoice, make merry," which is of uncertain origin. Perhaps from a Latinized verb formed from Frankish *wala- "good, well," from Proto-Germanic *wal- (source also of Old High German wallon "to wander, go on a pilgrimage"), from PIE root *wel- (2) "to wish, will" (see will (v.)), "but the transition of sense offers difficulties that are not fully cleared up" [OED]. Sense of "politely attentive to women" was adopted early 17c. from French. Attempts to distinguish this sense by accent are an 18c. artifice.

gallant (n.)

mid-15c., "man of fashion and pleasure," earlier "dissolute man, rake" (early 15c.); from gallant (adj.). As "one who is particularly attentive to women" probably by late 15c.

(https://www.etymonline.com/word/gallant)

In Noah Webster's 1828 American English Dictionary (the First American English Dictionary), he carries the term forward...

GAL'LANTRY, noun

1. Splendor of appearance; show; magnificence; ostentatious finery. [Obsolete or obsolescent.]

2. Bravery; courageousness; heroism; intrepidity. The troops entered the fort with great gallantry

3. Nobleness; generosity.

4. Civility or polite attentions to ladies.

5. Vicious love or pretensions to love; civilities paid to females for the purpose of winning favors; hence, lewdness; debauchery.

(http://webstersdictionary1828.com/Dictionary/Gallantry)

The LAST definition of the term was used by John Adams in his letter to the Massachusetts Militia to describe the types of character that would undermine the safeguards enshrined in the U.S. Constitution: "Avarice, ambition, revenge, or GALLANTRY, would break the strongest cords or our Constitution as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other."

(https://faithandflag.wordpress.com/2021/01/08/president-john-adams-full-letter-to-massachusetts-militia/)

According to the current Mirrian-Webster Online Edition, Gallatry may be defined as:
1archaic : gallant appearance
2a: an act of marked courtesy
b: courteous attention to a lady
c: amorous attention or pursuit
3: SPIRITED AND CONSPICUOUS BRAVERY [EMPHASIS ADDED]

(https://www.merriam-webster.com/dictionary/gallantry)

In the context that we use "Gallantry" today to describe acts of valor, I would gather -- from the evolution of the word -- is defined as a ostentatious demonstration of heroism befitting a truly chivalrous servant of his/her nation.

"Intrepidity" is the one I had to look up. I think they attempt to use the different words to recognize the spectrum of heroism...how far you put yourself out there, how much you took withering fire, how long you stayed in the fight and how much you accomplished after serious injury. I would put Valor and Courage on the lower end (it's listed on lower medals) and Gallantry and Intrepidity at the highest level. In the analysis for the higher medals (SS and above), they cover the whole story from all sources and witnesses and use several senior analysts to determine the level of award.