Perhaps a primary word; vigor ("great") (literally or figuratively) -- dominion, might(-ily), power, strength.
1. force, strength.
2. power, might: τό κράτος τῆς ἰσχύος αὐτοῦ, the might of his strength, Ephesians 1:19; Ephesians 6:10; τῆς δόξης αὐτοῦ, Colossians 1:11; κατά κράτος, mightily, with great power, ηὔξανε, Acts 19:20; metonymy, a mighty deed, a work of power: ποιεῖν κράτος (cf. ποιεῖν δυνάμεις), Luke 1:51.
3. dominion: in the doxologies, 1 Timothy 6:16; 1 Peter 4:11; 1 Peter 5:11; Jude 1:25; Revelation 1:6; Revelation 5:13; τίνος (the genitive of object), Hebrews 2:14 (τό Περσεων κράτος ἔχοντα, Herodotus 3, 69). (Synonym: see δύναμις, at the end.)