Old French behind bar taking responsibility while one is working there on security perhaps (10)
I believe the answer is:
lineofduty
'while one is working there on security perhaps' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'old french behind bar taking responsibility' is the wordplay.
I cannot quite see how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is found within the answer.
'french' could be 'f' and 'f' is found in the answer.
'bar' could be 'line' (I've seen this in other clues) and 'line' is found within the answer.
'responsibility' could be 'duty' (synonyms) and 'duty' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?