Halfbeak definition

Any of various slender, chiefly marine fishes of the family Hemiramphidae of warm waters, having a blue or green and silvery body and an elongated lower jaw that often has a bright red or orange tip.

Any of a family (Hemirhamphidae, order Atheriniformes) of small, long-bodied, tropical marine bony fishes with a greatly extended lower jaw and a short upper jaw.

(zoology) Any slender, marine fish of the family Hemiramphidae, having the upper jaw much shorter than the lower, the balahoo.