Titanium used with new metal (3)
I believe the answer is:
tin
'metal' is the definition.
(I know that tin is a type of metal)
'titanium used with new' is the wordplay.
'titanium' becomes 'Ti' (Ti is the chemical symbol for titanium).
'used with' says to put letters next to each other.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'ti'+'n'='TIN'
(Other definitions for tin that I've seen before include "Canister" , "A silvery-white metal often in cans" , "Silver-white element often used in food containers" , "With copper, makes bronze" , "Atomic number 50" .)