The Collaborative International Dictionary of English v.0.48:
Valvula \Val"vu*la\, n.; pl. Valvulae. [NL., dim. fr. L. valva fold, valve of a door.] (Anat.) A little valve or fold; a valvelet; a valvule. [1913 Webster]WordNet (r) 3.0 (2006):
valvula n 1: a small valve [syn: valvule, valvelet, valvula]