Declare legally invalid (5)

I believe the answer is:
annul
(Other definitions for annul that I've seen before include "Recall" , "Scrap" , "Make invalid" , "Cancel, say a law" , "Declare (a law) invalid" .)
I believe the answer is:
annul
(Other definitions for annul that I've seen before include "Recall" , "Scrap" , "Make invalid" , "Cancel, say a law" , "Declare (a law) invalid" .)