Roars (7)
I believe the answer is:
bellows
'roars' is the definition.
('bellow' can be a synonym of 'roar')
This is all the clue.
(Other definitions for bellows that I've seen before include "sings very loudly" , "Device that blows a strong current of air" , "Wind pump; shouts" , "Roars at part of the organ" , "Air blower for fire" .)