Downhill racer complicated risk with energy (5)
I believe the answer is:
skier
'downhill racer' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'complicated risk with energy' is the wordplay.
'complicated' indicates an anagram.
'with' means one lot of letters goes inside another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'risk' is an anagram of 'skir'.
'skir' going around 'e' is 'SKIER'.
Can you help me to learn more?
(Other definitions for skier that I've seen before include "He glides over snow, perhaps in sport" , "Sportsman who glides over snow" , "Winter sports person" , "Winter sportsperson" , "One on the piste" .)