Voids (6)
I believe the answer is:
annuls
'voids' is the definition.
('annul' can be a synonym of 'void')
This is the entire clue.
(Other definitions for annuls that I've seen before include "Repeals or rescinds" , "Declares invalid" , "Cancels, abolishes" , "Cancels, makes void" , "Renders boid" .)