The Collaborative International Dictionary of English v.0.48:

Keeled \Keeled\, a.
   1. (Bot.) Keel-shaped; having a longitudinal prominence on
      the back; as, a keeled leaf.
      [1913 Webster]

   2. (Zool.) Having a median ridge; carinate; as, a keeled
      scale.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Keel \Keel\, v. i. [imp. & p. p. Keeled; p. pr. & vb. n.
   Keeling.]
   1. To traverse with a keel; to navigate.
      [1913 Webster]

   2. To turn up the keel; to show the bottom.
      [1913 Webster]

   To keel over, to upset; to capsize. [Colloq.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

keeled
    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]