Exhausted writer found in street (5)
I believe the answer is:
spent
'exhausted' is the definition.
(I know that exhausted can be written as spent)
'writer found in street' is the wordplay.
'writer' becomes 'pen' (something which writes).
'found in' means one lot of letters goes inside another.
'street' becomes 'st' (abbreviation).
'pen' placed into 'st' is 'SPENT'.
(Other definitions for spent that I've seen before include "Worn out - after shopping?" , "Worn out having paid out money." , "Burned-out" , "Completely exhausted" , "Used up; exhausted" .)