The part of the mind that is aware of itself; the consciousness.

Alert, awake; with one's mental faculties active.

“The noise woke me, but it was another few minutes before I was fully conscious.”

Aware of one's own existence; aware of one's own awareness.

“Only highly intelligent beings can be fully conscious.”

Aware of, sensitive to; observing and noticing, or being strongly interested in or concerned about.

“I was conscious of a noise behind me.   a very class-conscious analysis”