Adverb from pro; prior, sooner -- before (that), ere.
see GREEK pro
1. an adverb previously,formerly (cf. πάλαι, 1): 3Macc. 5:28 3Macc. 6:4, 31; but never so in the N. T.
2. with the force of a conjunction, before, before that: with an accusative and aorist infinitive of things past (cf. Winers Grammar, § 44, 6 at the end; Buttmann, § 142, 3); πρίν Ἀβραάμ γενέσθαι, before Abraham existed, came into being, John 8:58; also πρίν ἤ (cf. Meyer on Matthew 1:18), Matthew 1:18; (Acts 7:2); with an aorist infinitive haying the force of the Latin future perfect, of things future (cf. Winer's Grammar, 332 (311)): πρίν ἀλέκτορα φωνῆσαι, before the cock shall have crowed, Matthew 26:34, 75; Mark 14:72; Luke 22:61; add, John 4:49; John 14:29; also πρίν ἤ, Mark 14:30; Acts 2:20 (where L T Tr WH text omit ἤ); πρίν ἤ, preceded by a negative sentence (Buttmann, § 139, 35), with the aorist subjunctive having the force of a future perfect in Latin (Buttmann, 231 (199)), Luke 2:26 (R G L T Tr marginal reading, but WH brackets ἤ), and R G in Luke 22:34; πρίν ἤ, followed by the optative of a thing as entertained in thought, Acts 25:16 (Winers Grammar, 297 (279); Buttmann, 230 (198)). Cf. Matthiae, § 522, 2, p. 1201f; Alexander Buttmann (1873) Gram. § 139, 41; Klotz ad Devar. ii. 2, p. 720ff; Winers Grammar (and Buttmann), as above.