Pink York gent out horse-riding (4-8)

I believe the answer is:

pony-trekking

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'riding' is the definition.
(pony-trekking is a kind of riding)

'pink york gent out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'pink'+'york'+'gent'='pinkyorkgent'
'pinkyorkgent' anagrammed gives 'PONY-TREKKING'.

'horse' is the link.
This may not be correct. It may belong to another bit of the clue.

Can you help me to learn more?

I've seen this clue in The Times.

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