Lewis & Short

dēfīnītīvē, adv., v. foll. art. fin.

dēfīnītīvus, a, um, adj. [definio].

  1. I. Definitive, explanatory. So in the rhet. lang. of Cicero: constitutio, Inv. 2, 17; cf. ib. 1, 13: causa, id. Top. 24 fin. And in the later jurid. Lat.: sententia, a decisive, definitive sentence, Cod. Just. 7, 45, 3; 7, 64, 10 al.
  2. II. In late Lat. = definitus, definite, distinct, plain: materia, Tert. adv. Herm. 38.
    Adv.: dēfīnītīvē, definitively, plainly, distinctly: pronuntiare, Tert. Car. Christ. 18: loqui, Cael. Aur. Acut. 1 praef.