Jealousy (4)
I believe the answer is:
envy
'jealousy' is the definition.
(jealousy is an envious feeling)
This is all the clue.
(Other definitions for envy that I've seen before include "Jealous longing" , "Feeling of grudging admiration" , "Jealousy, resentment" , "One of seven deadly sins" , "Be green" .)