careless in WordNet English dictionary

1. marked by lack of attention or consideration or forethought or thoroughness; not careful
   "careless about her clothes"; "forgotten by some careless person"; "a careless housekeeper"; "careless proofreading"; "it was a careless mistake"; "hurt by a careless remark"
   careless 
   
2. effortless and unstudied
   "an impression of careless elegance"; "danced with careless grace"
   careless 
   
3. (usually followed by `of') without due thought or consideration
   "careless of the consequences"; "crushing the blooms with regardless tread"
   careless  regardless