γνώστης, γνωστου, ὁ (a knower), an expert; a connoisseur: Acts 26:3. (Plutarch, Flam c. 4; Θεόςὁτῶνκρύπτωνγνώστης, Hist. Susanna, verse 42; of those who divine the future, 1 Samuel 28:3, 9, etc.)
Acts 26:3 - N-AMS GRK:μάλιστα γνώστην ὄντα σε NAS: especially because you are an expert in all KJV: thee to be expert in all customs INT: especially acquainted being you