The Collaborative International Dictionary of English v.0.48:
Ossiculum \Os*sic"u*lum\, n.; pl. Ossicula. [L., a little bone.] (Zool.) Same as Ossicle. [1913 Webster]WordNet (r) 3.0 (2006):
ossiculum n 1: a small bone; especially one in the middle ear [syn: ossicle, bonelet, ossiculum]