Abbott-Smith Manual Greek Lexicon
πιστόω (G4104)
1 πιστόω , -ῶ ( πιστός ), [in LXX chiefly for אמן ni.;] to make trustworthy (Thuc., III Ki 1:36 ), hence, to establish ( I Ch 17:14 ). Pass. and mid., to be assured of : c. acc. rei, II Ti 3:14 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain