Any possible disagreement (3)
I believe the answer is:
nay
'disagreement' is the definition.
(I've seen this before)
'any possible' is the wordplay.
'any' can be anagrammed to 'NAY'.
However, I'm unsure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for nay that I've seen before include "Negative response" , "No (dialect); or rather" , "even" , "No - a negative vote" , "Negative answer" .)