Possibly nailed in dishonest disavowal (6)
I believe the answer is:
denial
'dishonest disavowal' is the definition.
'denial' can be an answer for 'disavowal' (thesaurus). I'm unsure of the 'dishonest' bit.
'possibly nailed' is the wordplay.
'possibly' is an anagram indicator.
'nailed' is an anagram of 'DENIAL'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for denial that I've seen before include "Refusal to believe an unacceptable truth" , "Rejection or refusal" , "Refusal, abnegation" , "Nailed (anag.)" , "Declaration that something is untrue" .)