No sir! It's wrong for violinist's use (5)
I believe the answer is:
rosin
'violinist's use' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'no sir it's wrong' is the wordplay.
'it's wrong' is an anagram indicator.
'no'+'sir'='nosir'
'nosir' with letters rearranged gives 'ROSIN'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for rosin that I've seen before include "Rub it along the violin bow" , "Violin bow treatment" , "Wax for violin bow etc." , "It's put on bow" , "Fiddler's resin" .)