Stabbing item about to corrode (9)
I believe the answer is:
thrusting
'stabbing' is the definition.
The answer and definition can be both to do with contact as well as being present participle verbs.
Perhaps they are linked in a way I don't understand?
'item about to corrode' is the wordplay.
'item' becomes 'thing' (both can mean an object).
'about' means one lot of letters goes inside another.
'to corrode' becomes 'rust' ('rust' can be a synonym of 'corrode').
'thing' enclosing 'rust' is 'THRUSTING'.
Can you help me to learn more?
(Another definition for thrusting that I've seen is " ambitious".)