Time not working? Swell! (4)
I believe the answer is:
toff
'swell' is the definition.
(wealthy or high-class person)
'time not working?' is the wordplay.
'time' becomes 't' (abbreviation).
'not working?' becomes 'off' (switched off).
't'+'off'='TOFF'
(Other definitions for toff that I've seen before include "Dandy" , "An informal aristocrat" , "Wealthy and well-dressed member of the upper classes" , "Nob" , "Posh bloke (sl)" .)