Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
con-vĭtĭo, no perf., ātum, 1, v. a., to attack or injure at the same time (late Lat.): si sternutamento fuerint convitiati (of epi. leptics), Cael. Aur. Tard. 1, 4, 22.