Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
altercātor, ōris, m. [altercor], an orator who strives to conquer his antagonist by interrogatories, a disputant (cf. altercatio, II.): bonus altercator vitio iracundiae careat, Quint. 6, 4, 10; so id. 6, 4, 15; Front. Ver. Imper. 1.