carina

‖n. [ L., keel. ] 1. (Bot.) A keel. (a) That part of a papilionaceous flower, consisting of two petals, commonly united, which incloses the organs of fructification. (b) A longitudinal ridge or projection like the keel of a boat. [ 1913 Webster ]

2. (Zool.) The keel of the breastbone of birds. [ 1913 Webster ]

n. [ NL., fr. L. carina keel. ] (Zool.) A genus of oceanic heteropod Mollusca, having a thin, glassy, bonnet-shaped shell, which covers only the nucleus and gills. [ 1913 Webster ]

‖n. pl. [ NL., Fem. pl. fr. L. carinatus. See Carinate. ] A grand division of birds, including all existing flying birds; -- So called from the carina or keel on the breastbone. [ 1913 Webster ]