Pewter element (3)
I believe the answer is:
tin
'pewter element' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tin that I've seen before include "Atomic number 50" , "roofing material" , "Silvery-white metallic element" , "Silvery-white metal used in cans" , "Light metal" .)