Extended Strong's Greek Lexicon (Abbott-Smith based)
to strengthen
Usage: κραταιόω, -ῶ (late form of κρατύνω; κράτος) [in LXX chiefly for חָזַק ;] to strengthen; pass., to wax strong: Luk.2:40, 1Co.16:13; πνεύματι, Luk.1:80; δυνάμει κ. διὰ τ. πνεύματος, Eph.3:16.† (AS)