Trumpet's cousin (6)
I believe the answer is:
cornet
'trumpet's cousin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cornet that I've seen before include "Kind of trumpet or ice-cream holder" , "Musical instrument - ice cream" , "It's blown" , "Cone-shaped wafer" , "Trumpet-like instrument" .)