The Collaborative International Dictionary of English v.0.48:

Colloid \Col"loid\, a. [Gr. ko`lla glue + -oid. Cf.
   Collodion.]
   Resembling glue or jelly; characterized by a jellylike
   appearance; gelatinous; as, colloid tumors.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Colloid \Col"loid\, n.
   1. (Physiol. Chem.) A substance (as albumin, gum, gelatin,
      etc.) which is of a gelatinous rather than a crystalline
      nature, and which diffuses itself through animal membranes
      or vegetable parchment more slowly than crystalloids do;
      -- opposed to crystalloid.
      [1913 Webster]

   2. (Med.) A gelatinous substance found in colloid
      degeneration and colloid cancer.
      [1913 Webster]

   Styptic colloid (Med.), a preparation of astringent and
      antiseptic substances with some colloid material, as
      collodion, for ready use.
      [1913 Webster]

WordNet (r) 3.0 (2006):

colloid
    n 1: a mixture with properties between those of a solution and
         fine suspension