The Collaborative International Dictionary of English v.0.48:

Molle \Mol"le\, a. [See Moll.] (Mus.)
   Lower by a semitone; flat; as, E molle, that is, E flat.
   [1913 Webster]

WordNet (r) 3.0 (2006):

molle
    n 1: small Peruvian evergreen with broad rounded head and
         slender pendant branches with attractive clusters of
         greenish flowers followed by clusters of rose-pink fruits
         [syn: pepper tree, molle, Peruvian mastic tree,
         Schinus molle]