Duke meeting greedy king (5)
I believe the answer is:
david
'king' is the definition.
(I know that David is a king)
'duke meeting greedy' is the wordplay.
'duke' becomes 'd' (abbreviation).
'meeting' means one lot of letters go next to another.
'greedy' becomes 'avid' (synonyms).
'd'+'avid'='DAVID'
(Other definitions for david that I've seen before include "Dickens hero" , "The Psalmist" , "King of Judah and Israel, Saul's successor" , "Goliath's slayer" , "Hebrew king" .)