Jib (?), n. [Named from its shifting from side to side. See Jib, v. i.., Jibe.]
1. (Naut.) A triangular sail set upon a stay or halyard extending from the foremast or fore-topmast to the bowsprit or the jib boom. Large vessels often carry several jibs; as, inner jib; outer jib; flying jib; etc.
2. (Mach.) The projecting arm of a crane, from which the load is suspended.
Jib boom(Naut.), a spar or boom which serves as an extension of the bowsprit. It is sometimes extended by another spar called the flying jib boom. [Written also gib boom.] — Jib crane(Mach.), a crane having a horizontal jib on which a trolley moves, bearing the load. — Jib door(Arch.), a door made flush with the wall, without dressings or moldings; a disguised door. — Jib header(Naut.), a gaff-topsail, shaped like a jib; a jib-headed topsail. — Jib topsail(Naut.), a small jib set above and outside of all the other jibs. — The cut of one's jib, one's outward appearance. Sir W. Scott.