Lewis & Short

dīgressĭo, ōnis, f. [digredior], a parting, separating; a going away, departing, departure.

  1. * I. Lit. (in this signif. more freq. digressus): congressio, tum vero digressio nostra, Cic. Q. Fr. 1, 3, 4.
    More freq.,
  2. II. Trop., a going aside, deviation; esp. in lang., digression: qualis ad adjuvandum (sc. amicum) digressio (sc. a recto, referring to Cic. Lael. 17), Gell. 1, 3, 14: a proposita oratione, Cic. Brut. 85; so of speech, id. Inv. 1, 51; id. de Or. 2, 77, 312; 3, 53 fin.; Quint. 4, 2, 19; 9, 1, 28; 9, 2, 56 al.