Proclaim loudly (7)
![Ross](/clue/static/ross-mug.min.png)
'proclaim loudly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for trumpet that I've seen before include "Centre of daffodil flower" , "Brass musical instrument" , "Pert tum (anag.)" , "Metal wind instrument" , "Horn" .)