Lowest change for a dinar (5)
I believe the answer is:
nadir
'lowest' is the definition.
(I've seen this before)
'change for a dinar' is the wordplay.
'change for' indicates an anagram.
'dinar' anagrammed gives 'NADIR'.
(Other definitions for nadir that I've seen before include "All-time low" , "businessman formerly escaping justice" , "Point opposite the zenith" , "Given lowest place" , "Low-water mark" .)