Vegetation finally eaten by shy rabbit (4)
I believe the answer is:
cony
'rabbit' is the definition.
(synonyms)
'vegetation finally eaten by shy' is the wordplay.
'finally' says to take the final letters.
'eaten by' means one lot of letters goes inside another.
'shy' becomes 'coy' (coy can mean shy or modest).
The final letter of 'vegetation' is 'n'.
'n' placed inside 'coy' is 'CONY'.
(Other definitions for cony that I've seen before include "Rabbit" , "Perfect happiness" .)