Hummer’s discharge could be from this dog whistle (8)
I believe the answer is:
tailpipe
'hummer's discharge could be from this dog whistle' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'dog whistle' is the wordplay.
'dog' becomes 'tail' (synonyms).
'whistle' becomes 'pipe' (I've seen this before).
'tail'+'pipe'='TAILPIPE'
Can you help me to learn more?
(Other definitions for tailpipe that I've seen before include "Car exhaust (US)" , "End to an exhaust system" , "Rear section of exhaust" .)