/koh kee"neuh/ , n.
1. Also called pompano, butterfly-shell clam . a small clam, Donax variabilis, abundant in the intertidal zone of eastern and southern U.S. coastal beaches, having fanlike bands of various hues, the paired empty shells often spread in a butterfly shape.
2. any similar clam, esp. of the genus Donax.
3. a soft, whitish rock made up of fragments of marine shells and coral, used as a building material.
[ 1830-40, Amer.; coc(a ) shellfish ( concha; see CONCH) + -ina -INE 1 ]