Warrant Officer finally gets time-off (5)
I believe the answer is:
merit
'warrant' is the definition.
(I've seen this before)
'officer finally gets time-off' is the wordplay.
'finally' suggests the final letters.
'gets' means one lot of letters go next to another.
'off' is an anagram indicator.
The last letter of 'officer' is 'r'.
'r'+'time'='rtime'
'rtime' with letters rearranged gives 'MERIT'.
(Other definitions for merit that I've seen before include "Good point or quality" , "distinction" , "Rate" , "Value" , "Quality deserving reward" .)