Absent, on leave (3)
I believe the answer is:
off
I believe this is a double definition.
'absent' is the first definition.
(I've seen this in another clue)
'on leave' is the second definition.
(I've seen this in another clue)
(Other definitions for off that I've seen before include "Away, at a distance" , "away from the kerb" , "Not working - started" , "Fielding side" , "On holiday" .)