Unruly girl, out of time: liability inside bar, British (7)
I believe the answer is:
ladette
'unruly girl' is the definition.
(term for a laddish or boisterous young woman)
'time liability inside bar british' is the wordplay.
I cannot really see how this works, but
'time' could be 'ad' and 'ad' is found within the answer.
'bar' could be 'let' ('let' could historically mean hinder or prevent) and 'let' is found within the leftover letters.
The remaining letters 'te' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'out of' acts as a link.
(Other definitions for ladette that I've seen before include "Party girl?" , "Young woman with a loutish lifestyle?" , "Loutish girl" , "boozy girl" , "Young woman who acts as badly as a man" .)