Meaning

noun a band (usually elastic) worn around the leg to hold up a stocking (or around the arm to hold up a sleeve)

verb fasten with or as if with a garter

originFrom Middle English garter, from Old Northern French gartier, from Old French garet (compare Old French jartier, from jaret), from Gaulish *garrā, from Proto-Celtic *garros (“calf, shank”) (compare Cornish gar, Cornish gar,Middle Welsh garr, Old Irish gairr). Cognate with French jarretière.

Etymology from Wiktionary, CC BY-SA 3.0