One nominally finished with a ski? (4)
I believe the answer is:
pole
'one' is the definition.
The definition and answer can be both quantities as well as being singular nouns.
Maybe they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for pole that I've seen before include "Round rod of wood or metal" , "National from east" , "Long, round rod" , "(or north or eouth?)" , "This position is favourable in motor race" .)