Contradict (4)
'contradict' is the definition.
(denying is a kind of contradicting)
This is all the clue.
(Other definitions for deny that I've seen before include "Declare not to be true" , "Forbid; not agree" , "Refuse to admit the truth" , "Disown" , "Refuse; repudiate" .)
'contradict' is the definition.
(I know that contradict can be written as belie)
This is all the clue.
(Other definitions for belie that I've seen before include "Show to be untrue" , "Fail to justify" , "Confute" , "Contradict" .)
'contradict' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gainsay that I've seen before include "Challenge, dispute" , "Contradict, deny, dispute" , "Speak against" .)