Bugle (4)
I believe the answer is:
horn
'bugle' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for horn that I've seen before include "Instrument - rhino's appendage" , "being blown in the wind?" , "Brass musical instrument" , "Hollow outgrowth and musical instrument" , "Instrument - rhino's feature" .)