Drunk nurses working later (7)
I believe the answer is:
tonight
'later' is the definition.
(I've seen this before)
'drunk nurses working' is the wordplay.
'drunk' becomes 'tight' (slang term).
'nurses' is an insertion indicator (nurse can mean to hold onto or harbour).
'working' becomes 'on' (on can mean working or activated).
'tight' going around 'on' is 'TONIGHT'.
(Other definitions for tonight that I've seen before include "Hotting (anag.)" , "song from West Side Story" , "What follows today" , "Got thin (anag)" , "next retirement occasion" .)