light

noun \ ˈlīt \

Updated on: 15 Nov 2017

Definition of light

1 a : something that makes vision possible

b : the sensation aroused by stimulation of the visual receptors

c : electromagnetic radiation of any wavelength that travels in a vacuum with a speed of 299,792,458 meters (about 186,000 miles) per second; specifically : such radiation that is visible to the human eye

2 a : daylight

was up each morning at the first light
—Frank O'Connor

b : dawn

3 : a source of light: such as

a : a celestial body

As night fell the lights in the sky multiplied.

b : candle

put a light in the window

c : an electric light

4 a : a color of notable lightness : a light or pale color —usually plural

Bartlett allows his preliminary wash or grisaille to dry and then applies transparent layers of broken color. Into this wash he adds the lights and darks as they have been mapped out underneath.
—Harley Bartlett

b lights plural : clothing that is light in color

always washed his lights separately from his darks

5 archaic : sight 4a

6 a : spiritual illumination

the light shines in the darkness, and the darkness has not overcome it
—John 1:5 (Revised Standard Version)

b : inner light

c : enlightenment

reaching out and groping for a pathway to the light
—B. N. Cardozo

d : truth

7 a : public knowledge

facts brought to light

b : a particular aspect or appearance presented to view

saw the matter in a different light

8 : a particular illumination

9 : something that enlightens or informs

shed some light on the problem

10 : a medium (such as a window) through which light is admitted

11 lights plural : a set of principles, standards, or opinions

worship according to one's lights
—Adrienne Koch

12 : a noteworthy person in a particular place or field

a literary light among current writers

— see also leading light

13 : a particular expression of the eye

listened with a fiery light burning in her eyes
—Sherwood Anderson

14 a : lighthouse, beacon

b : traffic light

15 : the representation of light in art

16 : a flame for lighting something (such as a cigarette)

— in the light of

1 : from the point of view of

2 or in light of : in view of

In light of their findings, new procedures were established.

See light defined for English-language learners

See light defined for kids

Examples of light in a Sentence

The landscape was bathed in light.
a photograph taken in low light
the light of the moon
a mixture of light and shadow
The windows let fresh air and light into the room.
The lights suddenly went out.
The lights suddenly came on.
the twinkling lights of the city below
the bright lights of Broadway
The lights are on, so there must be somebody at home.

Origin and Etymology of light

Middle English, from Old English lēoht; akin to Old High German lioht light, Latin luc-, lux light, lucēre to shine, Greek leukos white

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

light Synonyms

Synonyms

blaze, flare, fluorescence, glare, gleam, glow, illumination, incandescence, luminescence, radiance, shine

Antonyms

nobody, noncelebrity

Related Words

flash, glimmer, glint, glitter, scintillation, shimmer, sparkle, twinkle; daylight, moonlight, sunlight, sunshine; afterglow, aureole (or aureola), aurora, beam, halo, ray, shaft, streak, stream, sunbeam; glisten, gloss, luster (or lustre), polish, reflection, sheen

Near Antonyms

blackness, dark, darkness, dimness, dusk, duskiness, gloom, night, shadow

Other Physics Terms

amplitude, centrifugal, centripetal, convection, gradient, hysteresis, kinetic, lase, quantum

light

adjective

Definition of light

1 : having light : bright

a light airy room

2 a : not dark, intense, or swarthy in color or coloring : pale

b of colors : medium in saturation and high in lightness

light blue

3 of coffee : served with extra milk or cream

Origin and Etymology of light

see ¹light

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

light

verb

Definition of light

lit play \ˈlit\ or lighted; lighting

intransitive verb

1 : to become light : brighten —usually used with up

her face lit up

2 : to take fire

3 : to ignite something (such as a cigarette) —often used with up

transitive verb

1 : to set fire to

2 a : to conduct with a light : guide

b : illuminate

rockets light up the sky

c : animate, brighten

a smile lit up her face

Origin and Etymology of light

see ¹light

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

light

adjective

Definition of light

1 a : having little weight : not heavy

b : designed to carry a comparatively small load

a light truck

c : having relatively little weight in proportion to bulk

aluminum is a light metal

d : containing less than the legal, standard, or usual weight

a light coin

2 a : of little importance : trivial

b : not abundant

light rain

a light lunch

3 a : easily disturbed

a light sleeper

b : exerting a minimum of force or pressure : gentle

a light touch

c : resulting from a very slight pressure : faint

light print

4 a : easily endurable

a light illness

b : requiring little effort

light work

5 : capable of moving swiftly or nimbly

light on his feet

6 a : frivolous 1a

light conduct

b : lacking in stability : changeable

light opinions

c : sexually promiscuous

7 : free from care : cheerful

8 : less powerful but usually more mobile than usual for its kind

light cavalry

a light cruiser

9 a : made with a lower calorie content or with less of some ingredient (such as salt, fat, or alcohol) than usual

b : having a relatively mild flavor

10 a : easily digested

a light soup

b : well leavened

a light crust

11 : coarse and sandy or easily pulverized

light soil

12 : dizzy, giddy

felt light in the head

13 : intended chiefly to entertain

light verse

light comedy

14 a : carrying little or no cargo

the ship returned light

b : producing goods for direct consumption by the consumer

light industry

15 : not bearing a stress or accent

a light syllable

16 : having a clear soft quality

a light voice

17 : being in debt to the pot in a poker game

three chips light

18 : short 5d

light on experience

19 : casual, occasional

a light smoker

—

lightish

play \ˈlī-tish\ adjective

Origin and Etymology of light

Middle English, from Old English lēoht; akin to Old High German līhti light, Latin levis, Greek elachys small

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

Synonym Discussion of light

easy, facile, simple, light, effortless, smooth mean not demanding effort or involving difficulty. easy is applicable either to persons or things imposing tasks or to activity required by such tasks.

- an easy college course

facile often adds to easy the connotation of undue haste or shallowness.

- facile answers to complex questions

simple stresses ease in understanding or dealing with because complication is absent.

- a simple problem in arithmetic

light stresses freedom from what is burdensome.

- a light teaching load

effortless stresses the appearance of ease and usually implies the prior attainment of artistry or expertness.

- moving with effortless grace

smooth stresses the absence or removal of all difficulties, hardships, or obstacles.

- a smooth ride

light

adverb

Definition of light

1 : lightly

2 : with little baggage

travel light

See light defined for English-language learners

First Known Use of light

before 12th century

light

verb

Definition of light

lit play \ˈlit\ or lighted; lighting

1 : dismount

2 : settle, alight

a bird lit on the lawn

3 : to fall unexpectedly —usually used with on or upon

4 : to arrive by chance : happen —usually used with on or upon

lit upon a solution

— light into

intransitive verb

: to attack forcefully

I lit into that food until I'd finished off the heel of the loaf
—Helen Eustis

Origin and Etymology of light

Middle English, from Old English līhtan; akin to Old English lēoht light in weight

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

LIGHT Defined for Kids

light

noun \ ˈlīt \

Definition of light for Students

1 : the bright form of energy given off by something (as the sun) that makes it possible to see

2 : a source (as a lamp) of light

Mr. Cohen flicks the lights off and on …
—Paula Danziger, Amber Brown

3 : daylight 1

4 : public knowledge

Facts were brought to light during the trial.

5 : understanding that comes from information someone has provided

The explanation shed light on the problem.

light

adjective

Definition of light for Students

lighter; lightest

1 : having light : bright

a light room

2 : not dark or deep in color

light

verb

Definition of light for Students

lit \ˈlit\ or lighted; lighting

1 : to make or become bright

2 : to burn or cause to burn

light a match

light the fire

light

adjective

Definition of light for Students

lighter; lightest

1 : having little weight : not heavy

a light suitcase

2 : less in amount or force than usual

a light breeze

a light touch

3 : not hard to bear, do, pay, or digest

light punishment

4 : active in motion

I felt light on my feet.

5 : free from care : happy

a light heart

6 : not dense and thick

light clouds

7 : intended mainly to entertain

light reading

—

lightly

adverb

—

lightness

noun

light

adverb

Definition of light for Students

: with little baggage

I prefer to travel light.

light

verb

Definition of light for Students

lit \ˈlit\ or lighted; lighting

1 : ²perch, settle

We saw a bird light on a twig.

2 : to come by chance

In time I lit on a solution.

Medical Dictionary

light

noun \ ˈlīt \

medical Definition of light

1 a : the sensation aroused by stimulation of the visual receptors

b : an electromagnetic radiation in the wavelength range including infrared, visible, ultraviolet, and X-rays and traveling in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : the part of this range that is visible to the human eye

2 : a source of light