Italian city underpinning church element (6)
I believe the answer is:
chrome
'element' is the definition.
(chrome is a kind of element)
'italian city underpinning church' is the wordplay.
'italian city' becomes 'rome' (I've seen this before).
'underpinning' says to put letters next to each other (I've seen this in other clues).
'church' becomes 'ch' (common abbreviation).
'rome' put after 'ch' is 'CHROME'.
(Other definitions for chrome that I've seen before include "Brilliant finish" , "Protective finish on motor vehicle fittings" , "Hard stuff for plating - yellow pigment" , "Metallic plate" , "Metallic element" .)