jillstrapEtymologyBy humorous analogy with jockstrap, Jock and Jill being male and female names respectively.jillstrap means A pelvic protector, a woman's equivalent of a man's jockstrap. Lexicurio rates it Sui generis — a strength score of 91 out of 100.nounA pelvic protector, a woman's equivalent of a man's jockstrap.