1. 
[syn: bulge, bump, hump, swelling, gibbosity, gibbousness, jut, prominence, protuberance, protrusion, extrusion, excrescence]
The Collaborative International Dictionary of English v.0.48:
Gibbous \Gib"bous\, a. [Cf. F. gibbeux. See Gibbose.]
   [1913 Webster]
   1. Swelling by a regular curve or surface; protuberant;
      convex; as, the moon is gibbous between the half-moon and
      the full moon.
      [1913 Webster]
            The bones will rise, and make a gibbous member.
                                                  --Wiseman.
      [1913 Webster]
   2. Hunched; hump-backed. [Obs.] --Sir T. Browne. --
      Gib"bous*ly, adv. -- Gib"bous*ness, n.
      [1913 Webster]
WordNet (r) 3.0 (2006):
gibbousness
    n 1: something that bulges out or is protuberant or projects
         from its surroundings; "the gun in his pocket made an
         obvious bulge"; "the hump of a camel"; "he stood on the
         rocky prominence"; "the occipital protuberance was well
         developed"; "the bony excrescence between its horns" [syn:
         bulge, bump, hump, swelling, gibbosity,
         gibbousness, jut, prominence, protuberance,
         protrusion, extrusion, excrescence]