Form of enumeration, one going up (11)

I believe the answer is:

mountaineer

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'one going up' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'form of enumeration' is the wordplay.
'form of' is an anagram indicator (the letters need to be in another 'form').
'enumeration' with letters rearranged gives 'MOUNTAINEER'.

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(Other definitions for mountaineer that I've seen before include "Person taking risks for a rise" , "Peak climber" , "person possibly at his peak?" , "Rock climber" , "Everest climber" .)

I've seen this clue in The Times.

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