javelin n.

late 15c., "a dart," the general word for "a spear intended to be thrown by hand, with or without a throwing stick," from Old French javeline (15c.), Old Provençal javelina, fem. diminutive of Old French javelot "a spear" (12c.), probably from Gaulish or another Celtic source (compare Old Irish gabul "fork;" Welsh gafl "fork," gaflach "feathered spear"), from Celtic *gablakko-, from PIE *ghabholo- "a fork, branch of a tree." Also found in Italian (giavelotto) and Middle High German (gabilot). Javelot itself was borrowed in Middle English (mid-15c.), but this is the form of the word that has endured.