καταδυναστεύωkatadynasteúō

to exercise dominion against, i.e. oppress

Greek (New Testament) · G2616

Meanings

to exercise power over, oppress: with accusative of person (Xen.; LXX, Micah 2:2, Wisdom 2:10, and elsewhere); with genitive of person, James 2:6 (ὑμᾶς, T); passive, Acts 10:38.

Same root

κατάkatá · G2596(prepositionally) down (in place or time), in varied relations (according to the case (genitive, dative or accusative) with which it is joined)
δυνάστηςdynástēs · G1413a ruler or officer

Where it appears

Appears 2 times in the Bible.

Acts 10:38 And you know that God anointed Jesus of Nazareth with the Holy Spirit and with power. Then Jesus went around doing good and healing all who were oppressed by the devil, for God was with him.
James 2:6 But you dishonor the poor! Isn’t it the rich who oppress you and drag you into court?

Source: G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), public domain.