Travel wearing metal cross (5)
I believe the answer is:
tigon
'cross' is the definition.
(offspring of a lion and a tiger)
'travel wearing metal' is the wordplay.
'travel' becomes 'go' ('go' can be a synonym of 'travel').
'wearing' means one lot of letters goes inside another.
'metal' becomes 'tin' (tin is a kind of metal**).
'go' put inside 'tin' is 'TIGON'.
(Other definitions for tigon that I've seen before include "Big hybrid of the cat family" , "Cross between tiger and lion" , "Hybrid offspring of two big cats" , "Animal" , "Tiger-lion hybrid" .)