Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sēmĭ-bōs, bŏvis, m., a half-ox (Ovidian): vir, i. e. the Minotaur, Ov. A. A. 2, 24; id. Tr. 4, 7, 18.