impulsĭo (inp-), ōnis, f. [impello], a pushing against. I. Lit., external pressure, influence: omnis coagmentatio corporis vel calore vel frigore vel aliqua impulsione vehementi labefactatur et frangitur
, Cic. Univ. 5, 14.— II. Trop., incitement, instigation, impulse. A. In gen.: impulsio est, quae sine cogitatione per quandam affectionem animi facere aliquid hortatur, ut amor, iracundia, aegritudo
, Cic. Inv. 2, 5, 17; cf. id. ib. 19; 2, 6, 20.— B. In partic.: ad hilaritatem impulsio, pleasantry, an incitement to merriment, = Gr. χαριεντισμός, a figure of speech, Cic. de Or. 3, 53, 205; Quint. 9, 1, 31; 9, 2, 3.