Leftover lira used carelessly (8)
I believe the answer is:
residual
'leftover' is the definition.
(I've seen this in another clue)
'lira used carelessly' is the wordplay.
'carelessly' indicates an anagram.
'lira'+'used'='liraused'
'liraused' with letters rearranged gives 'RESIDUAL'.
(Other definitions for residual that I've seen before include "Remaining at the end" , "surplus" , "Remaining; repeat royalty" , "Concerning what is left over" , "Leftover - used rail (anag)" .)