Wall Street's conclusion after forging a paper (7)
I believe the answer is:
parapet
'wall' is the definition.
(I know that parapet is a type of wall)
'street's conclusion after forging a paper' is the wordplay.
'conclusion' suggests the final letters.
'after' is a charade indicator (letters next to each other).
'forging' indicates an anagram (I've seen this in other clues).
The last letter of 'street' is 't'.
'a'+'paper'='apaper'
'apaper' is an anagram of 'parape'.
't' put after 'parape' is 'PARAPET'.
(Other definitions for parapet that I've seen before include "works" , "Wall, a low sort" , "defensive position" , "Militarily, it protects" , "Low wall round edge of balcony" .)