Block British article (3)
I believe the answer is:
ban
'block' is the definition.
(I've seen this in another clue)
'british article' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'article' becomes 'an' (indefinite article).
'b'+'an'='BAN'
(Other definitions for ban that I've seen before include "'Forbid, prohibit (3)'" , "Embargo" , "Hungarian governor < to forbid" , "Censor or proscribe" , "outlaw" .)