From 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]
From 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]