Drunk goes around talking about this evening (7)
I believe the answer is:
tonight
'this evening' is the definition.
(synonyms)
'drunk goes around talking about' is the wordplay.
'drunk' becomes 'tight' (I've seen this before).
'goes around' means one lot of letters goes inside another.
'talking about' becomes 'on' (on can mean relating to or about a certain subject).
'tight' going around 'on' is 'TONIGHT'.
(Other definitions for tonight that I've seen before include "late in the day" , "What follows today" , "Dark time ahead" , "Hotting up for after sundown" , "Hotting (anag.)" .)