ametabolous

from WordNet (r) 3.0 (2006)

ametabolous
    adj 1: undergoing slight or no metamorphosis [syn: {ametabolic},
           {ametabolous}] [ant: {metabolic}, {metabolous}]

from The Collaborative International Dictionary of English v.0.48

Ametabolic \A*met`a*bol"ic\, Ametabolous \Am`e*tab"o*lous\, a.
   (Zool.)
   Not undergoing any metamorphosis; as, ametabolic insects.
   Opposite of {metabolic}.
   [1913 Webster]

   2. undergoing only slight metamorphosis
      [WordNet 1.5]