Word Origin & History
"foresail of a ship," 1661, gibb, of uncertain origin, perhaps related to gibbet, from notion of a sail "hanging" from a masthead. Or perhaps from jib (v.) "shift a sail or boom" (1693), from Du. gijben, apparently related to gijk "boom or spar of a sailing ship." Said to indicate a ship's character
to an observant sailor as a strange vessel approaches at sea; also nautical slang for "face," hence cut of his jib.