Does opposite of careful mean conscious?

Answer 1

The word 'careful' means to pay attention to something as you do it - (to do it carefully)

The opposite of this would be not to pay attention to something you do as you do it - (to do it carelessly)

So the opposite of careful is careless

Here is a sentence : He was careful as he crossed the road and got to the other side OK, but she was careless as she crossed the road and was hit by a car.

Conscious means being generally awake and aware. The opposite of this would to be unconscious - someone who has been hit on the head and knocked out would be unconscious.

So the opposite of conscious is unconscious