(intransitive, slang, dated) To go away or depart, especially in haste or without notice.

The time at night at which artificial lights are to be turned off, a curfew or bedtime. / The prescribed bedtime for persons living in a boarding school or staying in a hospital.

Alternative form of lights-out / Unconsciousness.

present participle of light out

Third-person singular simple present indicative form of light out

(idiomatic) To cause someone to become unconscious, especially by striking him or her.

Synonym of punch someone's lights out

(idiomatic) To give someone a serious beating using one's fists; to punch someone until he or she is unconscious.