Colophony (5)
I believe the answer is:
rosin
'colophony' is the definition.
(I know that colophony can be written as rosin)
This is the entire clue.
(Other definitions for rosin that I've seen before include "What gives bite to strings" , "Violin bow treatment" , "Fiddler's resin" , "It's used on a violin bow" , "Rub it along the violin bow" .)