Journey in metal container makes one cross (5)
I believe the answer is:
tigon
'one cross' is the definition.
(offspring of a lion and a tiger)
'journey in metal container' is the wordplay.
'journey' becomes 'go' (I've seen this in other clues).
'in' indicates putting letters inside.
'metal container' becomes 'tin' (I've seen this in another clue).
'go' placed into 'tin' is 'TIGON'.
'makes' acts as a link.
(Other definitions for tigon that I've seen before include "cat cross" , "Cross between two big cats" , "Tiger-lion hybrid" , "Animal" , "Big hybrid of the cat family" .)