What Does "Till Death Do Us Part" Actually Mean?

The iconic marriage vow originated in the 1500s from the Book of Common Prayer used in the Anglican Christian churches in England :
"I [Name] take thee [Name] to be my wedded wife, to have and to hold from this day forward, for better, for worse, for richer, for poorer, in sickness, and in health, to love, and to cherish, till death us depart, according to God's holy ordinance: And thereto I plight thee my troth."


More info on Book of Common Prayer : https://en.wikipedia.org/wiki/Book_of_Common_Prayer
Bible Scriptures regarding marriage : https://www.openbible.info/topics/until_death_do_us_part