Rushes back to get a violin (5)
I believe the answer is:
strad
'a violin' is the definition.
(Stradivari abbreviation)
'rushes back' is the wordplay.
'rushes' becomes 'darts' (darting is a kind of rushing).
'back' is a reversal indicator.
'darts' written backwards gives 'STRAD'.
'to get' acts as a link.
(Other definitions for strad that I've seen before include "fiddle exposed" , "Old, very expensive violin (abbr)" , "Top-quality violin (abbr.)" , "Valuable violin (abbrev.)" , "Noted violin" .)