Source : Webster's Revised Unabridged Dictionary (1913)

Jib \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 jibe; 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. [Colloq.]
      --Sir W. Scott.

Jib \Jib\, v. i. [Connected with jibe; cf. OF. giber to shake.]
   To move restively backward or sidewise, -- said of a horse;
   to balk. [Written also {jibb}.] [Eng.]

Jib \Jib\, n.
   1. One that jibs, or balks; a jibber.

   2. A stationary condition; a standstill.

Jib \Jib\, v. t. & i. [imp. & p. p. {Jibbed}; p. pr. & vb. n.
   {Jibbing}.] Also Jibb \Jibb\ [Cf. {Jib} a sail, {Gybe}.]
   (Chiefly Naut.)
   To shift, or swing round, as a sail, boom, yard, etc., as in
   tacking.

Source : WordNet®

jib
     n : any triangular fore-and-aft sail (set forward of the
         foremast)
     v 1: refuse to comply [syn: {resist}, {balk}, {baulk}]
     2: shift from one side of the ship to the other; "The sail
        jibbed wildly" [syn: {jibe}, {gybe}, {change course}]
     [also: {jibbing}, {jibbed}]