The Collaborative International Dictionary of English v.0.48:

Perciformes \Per`ci*for"mes\, n. pl. [NL.] (Zool.)
   An extensive order of fishes, including the true perches
   (Percid[ae]); the pondfishes (Centrarchid[ae]); the
   sci[ae]noids (Sci[ae]nid[ae]); the sparoids (Sparid[ae]);
   the serranoids (Serranid[ae]), and some other related
   families.
   [1913 Webster] Percipience

WordNet (r) 3.0 (2006):

Perciformes
    n 1: one of the largest natural groups of fishes of both marine
         and fresh water: true perches; basses; tuna [syn:
         Perciformes, order Perciformes, Percomorphi, order
         Percomorphi]