G1226
διαβεβαιόω
to insist
δια-βεβαιόομαι, -οῦμαι to affirm confidently: Tit.3:8; before περί, 1Ti.1:7 (Cremer, 140).† (AS)
The KJV translates G1226 in the following manner:
affirm (2x), constantly (2x), that (2x)
Full Thayer's lexicon entry
διαβεβαιόομαι — diabebaióomai
διαβεβαιοομαι (διαβεβαιοῦμαι); middle to affirm strongly, assert confidently, (cf. Winer's Grammar, 253 (238)): περί τινο (Polybius 12, 11 (12), 6), 1Ti 1:7 (cf. WH's Appendix, p. 167); Tit 3:8. (Demosthenes, p. 220, 4; Diodorus, Dionysius Halicarnassus, Plutarch, Aelian)
2 occurrences
I Timothy (1), Titus (1)