Joy conserves energy -- taking five -- for ballet leap (9)
I believe the answer is:
elevation
'leap' is the definition.
(thesaurus)
'joy conserves energy taking five for ballet' is the wordplay.
I cannot really see how this works, but
'joy' could be 'io' and 'io' is located in the answer.
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is present in the answer.
'five' could be 'v' ('V' can be a synonym of 'five') and 'v' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for elevation that I've seen before include "Height - promotion" , "Drawing of the external face of a building" , "High point" , "Architectural drawing" , "Leave it on for altitude of a place" .)