Job exchange (5)
I believe the answer is:
trade
This clue is a double definition.
'job' is the first definition.
(I know that trade is a type of job)
'exchange' is the second definition.
(I know that trade is a type of exchange)
(Other definitions for trade that I've seen before include "job" , "Transaction" , "Commercial exchange of goods and services" , "Buy and sell, barter" , "Deal commercially" .)