The Collaborative International Dictionary of English v.0.48:

Mucor \Mu"cor\, prop. n. [L., fr. mucere to be moldy or musty.]
   (Bot.)
   A genus of minute fungi. The plants consist of slender
   threads with terminal globular sporangia; mold.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mucor
    n 1: any mold of the genus Mucor