On a trophy being returned (4)

I believe the answer is:

atop

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'on' is the definition.
Both the answer and definition are adverbs. Maybe you can see a link between them that I don't see?

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

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(Other definitions for atop that I've seen before include "Surmounting" , "On (poetic)" , "highly placed" , "Cooker heating element" , "In superior position" .)

I've seen this clue in The Sunday Times and The Times.

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