Careless

1. a. Not receiving care; uncared for.
2. a. Free from care or anxiety. hence, cheerful; light-hearted.
3. a. Having no care; not taking ordinary or proper care; negligent; unconcerned; heedless; inattentive; unmindful; regardless.
4. a. Without thought or purpose; without due care; without attention to rule or system; unstudied; inconsiderate; spontaneous; rash; as, a careless throw; a careless expression.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.