Mean clothes on this evening (7)
I believe the answer is:
tonight
'this evening' is the definition.
('tonight' can be a synonym of 'this evening')
'mean clothes on' is the wordplay.
'mean' becomes 'tight' ('tight' can be a synonym of 'mean'**).
'clothes' is an insertion indicator.
'tight' going around 'on' is 'TONIGHT'.
(Other definitions for tonight that I've seen before include "Got thin (anag)" , "after supper?" , "What follows today" , "next retirement occasion" , "song from West Side Story" .)