Blithe spirit (4)
I believe the answer is:
elan
'blithe spirit' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elan that I've seen before include "Dashing style" , "Energetic style - anagram of 3" , "Combination of style and vigour" , "Grass with edible grains" , "Dash in Paris" .)