Vehicle to move freight (5)
I believe the answer is:
cargo
'freight' is the definition.
(synonyms)
'vehicle to move' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'to move' becomes 'go' (to go is to move).
'car'+'go'='CARGO'
(Other definitions for cargo that I've seen before include "Load carried" , "What gets carried" , "Goods in transit" , "stuff to be carried by ship" , "Hold contents" .)