Careless, unsystematic (9)
I believe the answer is:
haphazard
I believe this is a double definition.
'careless' is the first definition.
(similar in meaning)
'unsystematic' is the second definition.
(thesaurus)
(Other definitions for haphazard that I've seen before include "Lacking order" , "Erratic" , "Careless or random" , "Slapdash, slipshod" , "Disorganised, random" .)