garrison (n.)

c. 1300, "store, treasure," from Old French garison "defense, protection, safety, security; crops, food; salvation; healing, recovery, cure" (Modern French guérison "cure, recovery, healing") from garir "take care of, protect, defend," from a Germanic source, from Proto-Germanic *war- "to protect, guard," from PIE root *wer- (4) "to cover."

Meaning "fortified stronghold" is from early 15c.; that of "body of troops in a fortress" is from mid-15c., a sense taken over from Middle English garnison "body of armed men stationed in a fort or town to guard it" (late 14c.), from Old French garnison "provision, munitions," from garnir "to furnish, provide" (see garnish (v.)).

"to place troops in," 1560s, from garrison (n.). Related: Garrisoned; garrisoning.