Loudspeaker — dog? (6)
I believe the answer is:
woofer
I believe this is a double definition.
'loudspeaker' is the first definition.
(I know that woofer is a type of loudspeaker)
'dog?' is the second definition.
(Other definitions for woofer that I've seen before include "Low-frequency speaker" , "Loudspeaker that reproduces lower frequency sounds" , "Lab possibly" , "Bass loudspeaker" , "Loudspeaker to reproduce lower sounds" .)