coralline adjective 3noun 2forms 3 adjective3 •Of, pertaining to, or resembling the material coral.The pigeon rocked itself backwards and forwards on the bough, swelling out its breast feathers and laying its coralline beak upon them. — 1934 •Of, relating to or pertaining to or resembling red algae of the family Corallinaceae. •Describing rock formed from the skeletons of such algae. noun2 •Any calcareous species of red algae of the family Corallinaceae. •An animal that resembles such a coral. formscorallines · more coralline · most coralline