Source : Webster's Revised Unabridged Dictionary (1913)

Valvula \Val"vu*la\, n.; pl. {Valvul[ae]}. [NL., dim. fr. L.
   valva fold, valve of a door.] (Anat.)
   A little valve or fold; a valvelet; a valvule.

Source : WordNet®

valvula
     n : a small valve (or valve-like structure) [syn: {valvule}, {valvelet}]