Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† cottăbus, i, m., = κότταβος (a social sport consisting in dashing a liquid upon a brazen vessel; v. Lidd. and Scott under κότταβος; hence humorously transf.), a clap, stroke: ne bubuli in te cottabi crebri crepent, Plaut. Trin. 4, 3, 4.