Lewis & Short

rĕ-gusto, āvi, ātum, 1, v. a., to taste again or repeatedly (very rare).

  1. I. Lit.: bilem suam regustantes, Sen. Prov. 3, 13: regustatum digito terebrare salinum, i. e. licked out, Pers. 5, 138.
  2. II. Trop.: illam (laudationem Lollii) legi, volo tamen regustare, i. e. to read again, Cic. Att. 13, 48, 2: crebro regusto litteras, id. ib. 13, 13, 3: ille Latinus ἀττικισμὸς ex intervallo regustandus, id. ib. 4, 17, 1.