X, defined by the crossword setter - that's what we hear in bar (7)
I believe the answer is:
exclude
'bar' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for exclude that I've seen before include "Rule out" , "Bar -- omit" , "Deny access to" , "Bar from entrance" , "Bar, ban" .)