Block pub ordering a cider (9)
I believe the answer is:
barricade
'block' is the definition.
(synonyms)
'pub ordering a cider' is the wordplay.
'pub' becomes 'bar' (both are drinking establishments).
'ordering' indicates anagramming the letters.
'a'+'cider'='acider'
'acider' anagrammed gives 'ricade'.
'bar'+'ricade'='BARRICADE'
(Other definitions for barricade that I've seen before include "Roadblock perhaps" , "Temporary obstruction" , "Block progress" , "Barrier, to block a street perhaps" , "Wall" .)