Misers may be careless (6)
I believe the answer is:
remiss
'careless' is the definition.
(I've seen this before)
'misers may be' is the wordplay.
'may be' indicates anagramming the letters.
'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" .)