Wiktionary
ventral fin
n. (context ichthyology English) A fin, usually paired, located ventrally below the pectoral fins of a fish.
WordNet
ventral fin
n. either of a pair of fins attached to the pelvic girdle in fishes that help control the direction of movement; correspond to hind limbs of a land vertebrate [syn: pelvic fin]
Usage examples of "ventral fin".
One ventral fin caught Farr with a side-swipe which sent him spinning against a tree trunk.
He was urged on by Sharkey, who was running down the ventral fin to assist.
One ventral fin caught Farr with a side-swipe which sent him spinning against a tree trunk&hellip.
At a thousand feet above the dry lake bed he pulled out of his dive and, with the slipstream roaring past his canopy, jettisoned his ventral fin.