1) Annuls 2) Undoes 1) Brings to naught 2) Cancels out 3) Counteracts 4) Countermands 5) Denies 6) Denies the truth of 7) Disestablishes 8) Makes ineffective 9) Makes not so 10) Makes null and void 11) Nullifies 12) Proves nonexistent 13) Renders invalid