Jump on blades (4)
I believe the answer is:
axel
'jump on blades' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for axel that I've seen before include "Jump executed on ice" , "What skater may do" , "A Torvill & Dean manoeuvre" , "Figure-skating jump" , "Figure skater's jump" .)