Keen desire for money (3)
I believe the answer is:
yen
This might be a double definition.
'keen desire' is the first definition.
'yen' can be an answer for 'desire' (yen can mean a longing or desire). I am unsure of the 'keen' bit.
'for money' is the second definition.
(Japanese currency)
Can you help me to learn more?
(Other definitions for yen that I've seen before include "Japanese currency; yearning" , "Strong desire" , "Intense desire for Japanese money" , "change in East" , "Itch, craving" .)