The Collaborative International Dictionary of English v.0.48:

Carinate \Car"i*nate\, Carinated \Car"i*na`ted\a. [L. carinatus,
   fr. carina keel.]
   Shaped like the keel or prow of a ship; having a carina or
   keel; as, a carinate calyx or leaf; a carinate sternum (of a
   bird).
   [1913 Webster]

WordNet (r) 3.0 (2006):

carinated
    adj 1: having a ridge or shaped like a ridge or suggesting the
           keel of a ship; "a carinate sepal" [syn: ridged,
           carinate, carinated, keeled]