The Collaborative International Dictionary of English v.0.48:

Lingua \Lin"gua\ (l[i^][ng]"gw[.a]), n.; pl. Lingu[ae]
   (l[i^][ng]"gw[=e]). [L., the tongue.] (Zool.)
   (a) A tongue.
   (b) A median process of the labium, at the under side of the
       mouth in insects, and serving as a tongue.
       [1913 Webster]

WordNet (r) 3.0 (2006):

lingua
    n 1: a mobile mass of muscular tissue covered with mucous
         membrane and located in the oral cavity [syn: tongue,
         lingua, glossa, clapper]