Barricade the street! (4)
I believe the answer is:
wall
This clue is a double definition.
'barricade' is the first definition.
(thesaurus)
'the street' is the second definition.
(Wall Street is an example)
(Other definitions for wall that I've seen before include "Stone fence" , "Barrier - side of room" , "Vertical divider or support" , "mechanical part" , "Brick construction" .)