The Collaborative International Dictionary of English v.0.48:
Unicameral \U`ni*cam"e*ral\, a. [Uni- + L. camera vault.] Having, or consisting of, a single chamber; -- said of a legislative assembly. [R.] --F. Lieber. [1913 Webster]WordNet (r) 3.0 (2006):
unicameral adj 1: composed of one legislative body [ant: bicameral]