German river's pronounced smell (5)

I believe the answer is:

odour

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'smell' is the definition.
(I know that smell can be written as odour)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for odour that I've seen before include "Stench" , "pervasive quality" , "Stink" , "Aroma or fragrance" , "A smell, good or bad" .)

I've seen this clue in The Telegraph.

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