Degas' heart captured by naked elbow (5)
I believe the answer is:
nudge
'elbow' is the definition.
('nudge' can be a synonym of 'elbow')
'degas' heart captured by naked' is the wordplay.
'heart' indicates the central letters.
'captured by' means one lot of letters goes inside another.
'naked' becomes 'nude' ('nude' can be a synonym of 'naked'**).
The centre of 'degas' is 'g'.
'g' inserted into 'nude' is 'NUDGE'.
(Other definitions for nudge that I've seen before include "Remind, prompt gently" , "Gently encourage" , "Shove" , "Give a reminder" , "Elbow someone gently" .)