The Greek verb dolioō means to deceive or to act with guile. Related to dolos (bait/trap/deceit), it describes the active practice of trickery and dishonesty. In the New Testament it appears in Romans 3:13 in Paul's catena of indictment against human sinfulness.
Paul quotes Psalm 5:9 LXX in Romans 3:13 — 'With their tongues they keep deceiving (dolioō)' — as part of a comprehensive portrait of humanity's corruption apart from God's grace. The word underscores that sin is not merely passive failure but active deceitfulness. The redeemed life is characterized by putting away all deceit and speaking truth in love (Ephesians 4:25).