unsaturated
    adj 1: not saturated; capable of dissolving more of a substance
           at a given temperature; "an unsaturated salt solution"
           [ant: concentrated, saturated]
    2: used of a compound (especially of carbon) containing atoms
       sharing more than one valence bond; "unsaturated fats" [ant:
       saturated]
    3: (of color) not chromatically pure; diluted; "an unsaturated
       red" [ant: pure, saturated]

Unsaturated \Un*sat"u*ra`ted\, a.
   1. Capable of absorbing or dissolving to a greater degree;
      as, an unsaturated solution.
      [1913 Webster]

   2. (Chem.) Capable of taking up, or of uniting with, certain
      other elements or compounds, without the elimination of
      any side product; thus, aldehyde, ethylene, and ammonia
      are unsaturated; benzene has three unsaturated bonds. The
      term is applied most commonly to compounds with a double
      or triple bond between two carbon atoms (as in ethylene).
      [1913 Webster +PJC]