collisus (post-Augustan): concursio (as act): concursus (as state): pugna: contentio (hostile collision): to be in collision, inter se pugnare (of things): with anything, pugnare cum re: repugnare alicui rei (Vid: Cic., Off., 3, 7, 34, and 12, 50): to come into collision with anybody, est mihi certamen cum aliquo: with anything, incurrere in aliquid: offendere ad aliquid: allidi ad aliquid (to strike against in general).