Lie and dissemble in opposition (6)
I believe the answer is:
denial
'opposition' is the definition.
(thesaurus)
'lie and dissemble' is the wordplay.
'lie and' anagrams to 'DENIAL'.
But, I am unsure how this is indicated.
'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" , "Negation" , "Rejection or refusal" , "Refusal to accept an unpalatable truth" , "Nailed (anag.)" .)