Men to label explosive element resistant to corrosion (5,5)
I believe the answer is:
noble metal
'element resistant to corrosion' is the definition.
(I've seen this before)
'men to label explosive' is the wordplay.
'explosive' indicates an anagram.
'men'+'to'+'label'='mentolabel'
'mentolabel' is an anagram of 'NOBLE METAL'.
(Other definitions for noble metal that I've seen before include "silver, say" , "element resistant to corrosion" .)