Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
bĭ-frons, ontis, adj. [bis], with two foreheads, or, in a more extended sense, with two faces, an epithet of Janus, Verg. A. 7, 180; 12, 198; Gav. Bass. ap. Macr. S. 1, 9, 13.