n.1 the soft glowing light from the sky when the sun is below the horizon, esp. in the evening.
2 the period of this.
3 a faint light.
4 a state of imperfect knowledge or understanding.
5 a period of decline or destruction.
Phrases and idioms:
twilight sleep Med. a state of partial narcosis, esp. to ease the pain of childbirth. twilight zone
1. an urban area that is becoming dilapidated.
2 any physical or conceptual area which is undefined or intermediate.
Etymology: ME f. OE twi- two (in uncert. sense) + LIGHT(1)