abrogate or arrogate? These two formal verbs are sometimes confused. To abrogate something such as a treaty or a right is to ‘annul’ or ‘abolish’ it. To arrogate is to ‘claim or seize something without justification’ – it is related to arrogant and usually occurs in the form arrogate something to oneself: She has recently arrogated to herself the role of decision-maker for the whole group.