Misers may be careless (6)
I believe the answer is:
remiss
'careless' is the definition.
(I know that careless can be written as remiss)
'misers may be' is the wordplay.
'may be' is an anagram indicator.
'misers' is an anagram of 'REMISS'.
(Other definitions for remiss that I've seen before include "Negligent, derelict" , "Derelict in duty" , "delinquent" , "Careless concerning a girl?" , "Negligent, slack" .)