noun
- any of various bony fishes of the subclass Actinopterygii, having strong slender rays, excluding the coelacanth and lungfish.
- Any of various bony fishes belonging to the subclass Actinopterygii, having fins supported by thin bony rays. Ray-finned fish evolved in the early Devonian Period and include most species of fish today. Also called actinopterygian Compare lobe-finned fish.