Lewis & Short

cantāmen, ĭnis, n. [canto, III.; cf. cano, II.; cantus, II. B., and carmen; lit. a charming with words; hence, abstr. pro concr.], a spell, charm, magic sentence, incantation (very rare), Prop. 4 (5), 4, 51; App. M. 2, p. 114; id. Mag. 40, p. 299: magicum, Prud. adv. Sym. 2, 176.