That part of the natural day when the sun is beneath the horizon, or the time from sunset to sunrise; esp., the time between dusk and dawn, when there is no light of the sun, but only moonlight, starlight, or artificial light.

Darkness; obscurity; concealment.

Intellectual and moral darkness; ignorance.

the time after sunset and before sunrise while it is dark outside

The period of time during any day that starts at the end of evening civil twilight and ends at the start of morning civil twilight. Fr: nuit

a shortening of nightfall; "they worked from morning to night"

The time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the American Air Almanac, converted to local time.