not paying enough attention to what one does: a careless typist.
not exact, accurate, or thorough: careless work.
done or said heedlessly or negligently; unconsidered: a careless remark.
not caring or troubling; having no care or concern; unconcerned (usually fol. by of, about, or in): careless of the rights of others; careless about one's behavior; careless in speech.
possessed or caused without effort or art; unstudied: careless beauty.