Hint - bar European entering Open (8)
I believe the answer is:
innuendo
'hint' is the definition.
(I've seen this before)
'bar european entering open' is the wordplay.
'bar' becomes 'inn' (I've seen this in other clues).
'european' becomes 'E' (abbreviation e.g. EU).
'entering' indicates putting letters inside.
'open' becomes 'undo' (I've seen this before).
'e' inserted into 'undo' is 'uendo'.
'inn'+'uendo'='INNUENDO'
(Other definitions for innuendo that I've seen before include "comment of sexual nature?" , "An unpleasant allusion or insinuation" , "Indirect remark" , "Oblique allusion" , "nudge nudge)" .)