Very large hint is placed inside bar (9)
I believe the answer is:
ostracise
'bar' is the definition.
(I've seen this before)
'very large hint is placed inside' is the wordplay.
'very large' becomes 'os' (abbreviation for oversize).
'hint' becomes 'trace' (synonyms).
'placed inside' means one lot of letters goes inside another.
'trace' going around 'is' is 'tracise'.
'os'+'tracise'='OSTRACISE'
(Other definitions for ostracise that I've seen before include "Cast out, blackball" , "Blackball, send to Coventry" , "Exclude, blackball" , "Banish from group" , "Shun, exclude" .)