Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. fronto, ōnis, m. amplif. [2. frons], one who has a broad forehead: ecquos naevum habere? ecquos silos, flaccos, frontones, capitones? Cic. N. D. 1, 29, 80.
Hence,