The phrase "un did" can refer to the act of undoing or reversing an action, state, or decision. Synonyms for this term include undo, reverse, cancel, rescind, nullify, revoke, annul, invalidate, repeal, and retract. Each of these synonyms carries a slightly different connotation depending on the context in which they are used. For example, revoke and annul may be used in a legal or official context, while cancel and retract may be used in a more informal setting. Regardless of the synonym used, the concept behind "un did" remains the same - the reversal of a previous action or decision.