(intransitive, cricket, of the umpires) To ask the batsmen if they wish to continue playing in conditions of poor light. If they do not, play is suspended for bad light.

(cricket) A weather condition where the light is so poor that the umpires feel that to continue playing would be dangerous. / (figuratively) An unfavourable presentation.

(uncountable) Light, having a mixture of frequencies, being perceived as having no specific colour; such as sunlight. / (countable) A white-coloured light or lamp

(physics) light in which the electric and magnetic fields each vibrate in a single plane

synchrotron radiation

A traffic light in its green state (indicating that vehicles may proceed). / (idiomatic) Approval, or permission to proceed.

(physics) The part of the electromagnetic spectrum, between infrared and ultraviolet, that is visible to the human eye.

(uncountable) Light in the ultraviolet part of the spectrum. / (countable) A light bulb that emits ultraviolet light; a black light.

(countable) A light bulb that emits ultraviolet light, usually used to create the illusion that anything white is glowing. / (uncountable, slang) ultraviolet radiation/light

A source of illumination.