Obtained leave at the end of August (3)
I believe the answer is:
got
'obtained' is the definition.
('get' can be a synonym of 'obtain')
'leave at the end of august' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'at the end of' indicates one should take the final letters.
The final letter of 'august' is 't'.
'go'+'t'='GOT'
(Other definitions for got that I've seen before include "Acquired" , "Landed" , "Received; understood" , "Caught" , "Obtained" .)