Appeal of an adventurous expedition (7)

I believe the answer is:

request

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'appeal' is the definition.
(I know that appeal is a more specific form of the action request)

'an adventurous expedition' is the wordplay.
'an adventurous' becomes 're' (I can't explain this - if you can you should believe this answer much more).
'expedition' becomes 'quest' (I've seen this in other clues).
're'+'quest'='REQUEST'

'of' is the link.

Can you help me to learn more?

(Other definitions for request that I've seen before include "bidding" , "Petition" , "Application" , "Call for" , "Suit" .)

I've seen this clue in The Daily Express.

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