Webster's Revised Unabridged Dictionary · 1913

Acanthopterygii

Acanthopterygii ({not transcribed}) , noun, plural

[New Latin, from Greek {not transcribed} thorn + {not transcribed} fin, dim. from {not transcribed} wing.]

(Zoology) An order of fishes having some of the rays of the dorsal, ventral, and anal fins unarticulated and spinelike, as the perch.