What is the meaning of careless?

adjective

• Marked by lack of attention or consideration or forethought or thoroughness; not careful.
  • usage: "careless about her clothes"; "forgotten by some careless person"; "a careless housekeeper"; "careless proofreading"; "it was a careless mistake"; "hurt by a careless remark"
• Effortless and unstudied.
  • usage: "an impression of careless elegance"; "danced with careless grace"
• Usually followed by `of'. ( without due thought or consideration)
  • usage: "careless of the consequences"; "crushing the blooms with regardless tread"
  • synonyms: regardless