From Latin 'abrogare' — literally asking the Roman people to vote a law away. Formal annulment by authority.
To repeal or do away with (a law, right, or formal agreement); to abolish by authoritative action.
From Latin 'abrogāre' (to repeal, to annul a law), from 'ab-' (away from) + 'rogāre' (to ask, to propose a law), from PIE *h₃reǵ- (to straighten, to direct, to rule). In Roman legislative procedure, to 'abrogate' a law was to ask the people to vote it away — the formal reverse of 'rogāre lēgem' (to propose a law). The root *h₃reǵ- also produced Latin 'rēx' (king), 'regere' (to rule), and English 'right' through Germanic *rehtaz. The prefix 'ab-' (from PIE *h₂epo, away from) signals removal or reversal. Related legal Latin: 'derogāre' (to partially repeal), 'interrogāre' (to ask between
Roman law distinguished between 'abrogātiō' (complete repeal of a law), 'dērogātiō' (partial repeal — taking away some provisions), and 'obrogātiō' (modification by passing a new law that contradicts the old one). English inherited 'abrogate' and 'derogate' but not 'obrogate' — a gap in the system that legal Latin would have filled neatly.