Leaving during coffee (3)
I believe the answer is:
off
'leaving' is the definition.
(as in 'I'm off')
'during coffee' is the wordplay.
'during' indicates a hidden word.
'OFF' is hidden within 'coffee'.
(Other definitions for off that I've seen before include "On holiday" , "Discontinued" , "Rancid or not in operation" , "Turned, sour" , "start to race" .)