horsehairEtymologyFrom Middle English hors her, horshere, hors-here, hors heer (also hors-hore), equivalent to horse + hair. Compare Old Norse hross-hár (“horsehair”).horsehair means The hair of a horse, especially from the mane and tail, used for upholstery. Lexicurio rates it Sui generis — a strength score of 85 out of 100.nounThe hair of a horse, especially from the mane and tail, used for upholstery.A fabric made from this.