Thayer's Greek LexiconSTRONGS NT 1650: ἔλεγχος
ἔλεγχος, ἐλέγχου, ὁ (ἐλέγχω);
1. a proof, that by which a thing is proved or tested (τό πρᾶγμα τόν ἔλεγχον δώσει, Demosthenes 44, 15 (i. e. in Philippians 1:15); τῆς εὐψυχίας, Euripides, Herc. fur. 162; ἐνθαδ' ὁ ἔλεγχος τοῦ πράγματος, Epictetus diss. 3, 10, 11; others): τῶν (or rather, πραγμάτων) οὐ βλεπομένων, that by which invisible things are proved (and we are convinced of their reality), Hebrews 11:1 (Vulg.argumentumnonapparentium (Tdf.rerumarg.nonparentum)); (others take the word here (in accordance with the preceding ὑπόστασις, which see) of the inward result of proving viz. a conviction; see Lünem, at the passage).
2. conviction (Augustine,convictio): πρός ἔλεγχον, for convicting one of his sinfulness, 2 Timothy 3:16 R G. (Euripides, Plato, Demosthenes, others; the Sept. chiefly for תּוכַחַת.)