Agent runs after rent? (6)
I believe the answer is:
broker
'agent' is the definition.
(synonyms)
'runs after rent?' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'after' says to put letters next to each other.
'rent?' becomes 'broke' (past tense of rend - to break or tear).
'r' after 'broke' is 'BROKER'.
(Other definitions for broker that I've seen before include "He buys and sells for others - say stocks" , "Insurance or investment agent" , "One acts as an agent for others in buying and selling" , "A dealer in stocks and shares" , "Negotiate with" .)