Nonconformist losing heart in dance (4)
I believe the answer is:
reel
'dance' is the definition.
(reel is a kind of dance)
'nonconformist losing heart' is the wordplay.
'nonconformist' becomes 'rebel' (rebel is a kind of nonconformist).
'losing heart' says to hollow out the word (remove centre letters).
'rebel' with its centre taken out is 'REEL'.
'in' acts as a link.
(Other definitions for reel that I've seen before include "Lively dance; bobbin" , "Winding spool on a fishing rod" , "Lively dance or fishing rod controller" , "Dance - swim" , "Stagger with rod winder" .)