The Collaborative International Dictionary of English v.0.48:

Rostrate \Ros"trate\, Rostrated \Ros"tra*ted\, a. [L. rostratus,
   fr. rostrum a beak. See Rostrum.]
   1. Having a process resembling the beak of a bird; beaked;
      rostellate.
      [1913 Webster]

   2. Furnished or adorned with beaks; as, rostrated galleys.
      [1913 Webster]