Sounding gruff and put out by Amish traffic (5,3,5)

I believe the answer is:

horse and sulky

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'amish traffic' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'sounding gruff and put out' is the wordplay.
'sounding' shows a homophone (sound like).
'gruff' becomes 'hoarse' (synonyms).
'put out' becomes 'sulky' (I can't explain this - if you can you should give a lot more credence to this answer).
'hoarse' is a homophone of 'horse'.
'horse'+'and'+'sulky'='HORSE AND SULKY'

'by' acts as a link.

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I've seen this clue in the Sydney Morning Herald.

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