Assume performance banning women's ruled out (8)
I believe the answer is:
shoulder
'assume performance' is the definition.
'shoulder' can be an answer for 'assume' (shoulder can mean to assume or take on). I am not certain of the 'performance' bit.
'banning women's ruled out' is the wordplay.
'banning women' becomes 'sho' (I can't explain this - if you can you should give a lot more credence to this answer).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'ruled' is an anagram of 'ulder'.
'sho'+'ulder'='SHOULDER'
(Other definitions for shoulder that I've seen before include "Body part of a strange old usher" , "Bear (burden); joint" , "Undertake (burden)" , "On the side of the road, it might be hard" , "Bear < to push" .)