1. actinopterygian - Noun
2. actinopterygian - Adjective
actinopterygian (plural actinopterygians)
(zoology) Any of the ray-finned fish of the taxonomic class Actinopterygii.
actinopterygian (comparative more actinopterygian, superlative most actinopterygian)
Of the nature of fish of the class Actinopterygii.