Freight company transporting a case of Riesling (5)
I believe the answer is:
cargo
'freight' is the definition.
(I know this)
'company transporting a case of riesling' is the wordplay.
'company' becomes 'co' (abbreviation).
'transporting' is an insertion indicator.
'case of' says to hollow out the word (remove centre letters) (outsides of).
'riesling' with its middle taken out is 'rg'.
'a'+'rg'='arg'
'co' going around 'arg' is 'CARGO'.
(Other definitions for cargo that I've seen before include "What gets carried" , "Load carried" , "Goods carried by vessel or vehicle" , "Shipment" , "Goods carried on ship or plane" .)