Lewis & Short

concursĭo, ōnis, f. [concurro, II.], a running or meeting together, a concurrence, concourse (several times in Cic.; elsewhere rare).

  1. I. In gen.: atomorum, Cic. Ac. 1, 2, 6: ut (corpora) concursionibus inter se cohaerescant, id. Fin. 1, 6, 17: stellarum, Gell. 14, 1, 29: crebra vocum, Cic. Or. 44, 151; cf.: crebrae vocalium, Auct. Her. 4, 12, 18: fortuitorum, Cic. Top. 20, 76.
  2. II. Esp., in rhet., a figure of speech, consisting of an emphatic repetition of the last words of a sentence, Gr. συμπλοκή: concursio et impetus in eadem verba, Cic. de Or. 3, 54, 206 (quoted by Quint. 9, 1, 33); cf. Auct. Her. 4, 14, 20.