Slipshod, slapdash (8)
I believe the answer is:
careless
This clue is a double definition.
'slipshod' is the first definition.
(similar in meaning)
'slapdash' is the second definition.
(similar in meaning)
(Other definitions for careless that I've seen before include "'Thoughtless, inattentive (8)'" , "Inattentive and negligent" , "Cavalier" , "Sloppy" , "impetuous" .)