Get rid of five hundred yen (5)
I believe the answer is:
ditch
'get rid' is the definition.
(I've seen this before)
'five hundred yen' is the wordplay.
'five hundred' becomes 'd' ('D' can be a synonym of 'five hundred').
'yen' becomes 'itch' (I've seen this before).
'd'+'itch'='DITCH'
'of' acts as a link.
(Other definitions for ditch that I've seen before include "Abandon; one dug" , "give up" , "long depression" , "Drainage trench" , "Excavated channel" .)