Unconventional description of policeman having finished duty (7)
I believe the answer is:
offbeat
'unconventional' is the definition.
(similar in meaning)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for offbeat that I've seen before include "Odd, unconventional" , "Quirky" , "Unusual, not ordinary - or rhythmic" , "rather unorthodox" , "Unusual or unconventional - perhaps in music" .)