monolingual

from WordNet (r) 3.0 (2006)

monolingual
    adj 1: using or knowing only one language; "monolingual
           speakers"; "a monolingual dictionary" [ant:
           {multilingual}]
    n 1: a person who knows only one language

from The Collaborative International Dictionary of English v.0.48

monolingual \mon`o*lin"gual\ adj.
   Using or knowing only one language; as, monolingual speakers;
   a monolingual dictionary. Opposite of {multilingual}.
   [WordNet 1.5]

[email protected]