Didn't accept the truth of (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
denied
(Other definitions for denied that I've seen before include "Refused to admit (the truth)" , "Refused to acknowledge, said it's not true" , "Contradicted" , "Refused to admit and refused access to" , "Refused to give (someone something)" .)