1. 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 jibe; as, inner jib; outer jib; flying jib; etc.
2. (Science: machinery) The projecting arm of a crane, from which the load is suspended. Jib boom, a small jib set above and outside of all the other jibs. The cut of one's jib, one's outward appearance.
Origin: Named from its shifting from side to side. See jib, Jibe.