Source : Webster's Revised Unabridged Dictionary (1913)

Acanthopterygian \Ac`an*thop`ter*yg"i*an\, a. (Zo["o]l.)
   Belonging to the order of fishes having spinose fins, as the
   perch. -- n. A spiny-finned fish.

Source : WordNet®

acanthopterygian
     n : a teleost fish with fins that are supported by sharp
         inflexible rays [syn: {spiny-finned fish}] [ant: {soft-finned
         fish}]