The Collaborative International Dictionary of English v.0.48:

Multivocal \Mul*tiv"o*cal\, a. [Multi- + vocal.]
   Signifying many different things; of manifold meaning;
   equivocal. "An ambiguous multivocal word." --Coleridge.
   [1913 Webster] -- n. A multivocal word. [R.] --Fitzed. Hall.
   [1913 Webster]