Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† antĭsŏphista, ae, m., = ἀντισοφιστής, a counter-sophist, i. e. a grammarian who takes the opposite side of a question (only post-Aug.), Quint. 11, 3, 127; Suet. Tib. 11; so id. Gram. 9.