Denial of what's true about a bit of fuss (7)
I believe the answer is:
refusal
'denial' is the definition.
(I know that refusal is a type of denial)
'what's true about a bit of fuss' is the wordplay.
I cannot quite see how this works, but
'about' could be 're' ('re' means regarding or about) and 're' is found in the answer.
'a' is found in the answer.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for refusal that I've seen before include "(Horse) failure to jump" , "Possibly first option to buy" , "Chance to decline" , "regrets?" , "Declining of an offer" .)