Rumanian money that is left over (3)
I believe the answer is:
lei
'rumanian money' is the definition.
'lei' can be an answer for 'money' (plural of 'leu', Romanian currency). I'm unsure of the 'rumanian' bit.
'that is left over' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'left' becomes 'L' (common abbreviation).
'over' is a reversal indicator.
'ie'+'l'='iel'
'iel' backwards is 'LEI'.
Can you help me to learn more?
(Other definitions for lei that I've seen before include "Polynesian garland of flowers" , "Garland of flowers in Hawaii" , "neck decoration" , "Flower garland of Hawaii" , "Hawaiian necklace of flowers" .)