The Collaborative International Dictionary of English v.0.48:

Vallecula \Val*lec"u*la\, n.; pl. Valleculae. [NL., dim. fr.
   L. vallis, valles, a valley.]
   [1913 Webster]
   1. (Anat.) A groove; a fossa; as, the vallecula, or fossa,
      which separates the hemispheres of the cerebellum.
      [1913 Webster]

   2. (Bot.) One of the grooves, or hollows, between the ribs of
      the fruit of umbelliferous plants.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vallecula
    n 1: (anatomy) any furrow or channel on a bodily structure or
         part [syn: groove, vallecula]