Duck eaten by greedy duck (5)
I believe the answer is:
avoid
'duck' is the definition.
(thesaurus)
'duck eaten by greedy' is the wordplay.
'duck' becomes 'o'.
'eaten by' indicates putting letters inside.
'greedy' becomes 'avid' ('avid' can be a synonym of 'greedy').
'o' inserted into 'avid' is 'AVOID'.
(Other definitions for avoid that I've seen before include "Elude" , "Prevent from happening; nullify (law)" , "Shirk" , "Bypass" , "Stay away from or circumvent" .)