The antonyms for the phrase "give allegiance to" include disown, reject, refuse, renounce, and abjure. When someone disowns a person or a belief, they reject it completely, refusing to recognize it. Refusing allegiance to something means that one does not owe any loyalty or devotion to it. Renouncing means to give up or relinquish one's allegiance or association with something, whereas abjuring involves the act of formally rejecting something, typically due to moral or ethical reasons. In essence, the antonyms for giving allegiance to signify a refusal of loyalty, devotion, and association with something.