n.; pl. cerata [Gr. keras, horn]1. A horn or horn-like appendage.2. (MOLLUSCA: Gastropoda)In some Nudibranchia, numerous projections that act as gills on the dorsal body surface, may be club shaped or grapelike and usually brilliantly colored in red, yellow, orange, blue, green, or a combination of colors; functioning in respiration, containing blood from the hemocoel and tubular branches of the digestive gland.
Online Dictionary of Invertebrate Zoology. A.R. Maggenti and S.L. Gardne. 2005.