A poor rhyme for greedy (5)
I believe the answer is:
needy
'a poor' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for needy that I've seen before include "Hard up" , "lacking resources" , "Penurious" , "Poverty-stricken" , "Necessitous" .)