Is he grumbling about the old-fashioned transport? (7)

I believe the answer is:

growler

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'is he grumbling about the old-fashioned transport?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

This is the entire clue.

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(Other definitions for growler that I've seen before include "Dog perhaps" , "Perhaps bear" , "Iceberg" , "Unfriendly dog" .)

I've seen this clue in the Evening Standard.

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