Exception? Eccentric? Unacceptable (3,3,3)
I believe the answer is:
odd man out
'exception? eccentric?' is the definition.
'odd man out' can be an answer for 'eccentric?' (I've seen this before). I am unsure of the 'exception?' bit.
'unacceptable' is the wordplay.
I cannot quite see how this works, but
'unacceptable' could be 'out' (I've seen this in other clues) and 'out' is located in the answer.
The remaining letters 'oddman' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for odd man out that I've seen before include "Nonconformist" , "that doesn't match the rest?" , "One unlike the others" , "film starring James Mason" , "Method of selection" .)