careless

Universal Words adjective 1 not giving enough attention and thought to what you are doing, so that you make mistakes: It was careless of me to leave the door open. * Don't be so careless about / with spelling. * a careless worker / driver 2 resulting from a lack of attention and thought: a careless mistake / error 3 ~ of sth (formal) not at all worried about sth: He seemed careless of his own safety. 4 not showing interest or effort SYNCASUAL: She gave a careless shrug. * a careless laugh / smile carelessly adverb: Someone had carelessly left a window open. * She threw her coat carelessly onto the chair. * 'I don't mind,' he said carelessly. carelessness noun [U]: a moment of carelessness