Abandon having time off (5)
I believe the answer is:
leave
I believe this is a double definition.
'abandon' is the first definition.
(to abandon something is to leave it behind)
'time off' is the second definition.
(leave is a kind of time off)
'having' acts as a link.
(Other definitions for leave that I've seen before include "taken by those on the way out" , "Time off; go" , "Go (5)" , "Soldier's holiday" , "Desert" .)