Largely excused, lolled around rear of bar: perfect (9)
I believe the answer is:
exemplary
'perfect' is the definition.
(I've seen this before)
'largely excused lolled around rear of bar' is the wordplay.
'largely' means to remove the last letter.
'excused' becomes 'exempt' (similar in meaning).
'lolled' becomes 'idled' (I've seen this in another clue).
'around' indicates the central letters.
'rear of bar' becomes 'ary' (I can't explain this - if you can you should believe this answer much more).
The centre of 'idled' is 'l'.
'exempt' with its final letter taken away is 'exemp'.
'exemp'+'l'+'ary'='EXEMPLARY'
(Other definitions for exemplary that I've seen before include "Worthy of imitation" , "Outstandingly good, others should imitate" , "Perfect" , "warning" , "Ideal" .)