[ lahyt ]
See synonyms for: lightlightedlighterlightest on

  1. something that makes things visible or affords illumination: All colors depend on light.

  2. Physics.

    • Also called lu·mi·nous en·er·gy, radiant energy. electromagnetic radiation to which the organs of sight react, ranging in wavelength from about 400 to 700 nanometers and propagated at a speed of 186,282 miles per second (299,972 kilometers per second), considered variously as a wave, a stream of particles, or a quantum phenomenon.

    • a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays.

  1. the sensation produced by stimulation of the organs of sight.

  2. an illuminating agent or source, as the sun, a lamp, or a beacon.

  3. the radiance or illumination from a particular source: the light of a candle.

  4. the illumination from the sun; daylight: We awoke at the first light.

  5. daybreak or dawn: when light appeared in the east.

  6. daytime: Summer has more hours of light.

  7. a particular light or illumination in which an object seen takes on a certain appearance: viewing the portrait in dim light.

  8. a device for or means of igniting, as a spark, flame, or match: Could you give me a light?

  9. a traffic light: Don't cross till the light changes.

  10. the aspect in which a thing appears or is regarded: Try to look at the situation in a more cheerful light.

  11. the state of being visible, exposed to view, or revealed to public notice or knowledge; limelight: Stardom has placed her in the light.

  12. a person who is an outstanding leader, celebrity, or example; luminary: He became one of the leading lights of Restoration drama.

  13. Art.

    • the effect of light falling on an object or scene as represented in a picture.

    • one of the brightest parts of a picture.

  14. a gleam or sparkle, as in the eyes.

  15. a measure or supply of light; illumination: The wall cuts off our light.

  16. spiritual illumination or awareness; enlightenment.

  17. Architecture.

    • Also called day. one compartment of a window or window sash.

    • a window, especially a small one.

  18. mental insight; understanding.

  19. lights, the information, ideas, or mental capacities possessed: to act according to one's lights.

  20. a lighthouse.

  21. Archaic. the eyesight.

adjective,light·er, light·est.
  1. having light or illumination; bright; well-lighted: the lightest room in the entire house.

  2. pale, whitish, or not deep or dark in color: a light blue.

  1. (of coffee or tea) containing enough milk or cream to produce a light color.

verb (used with object),light·ed or lit, light·ing.
  1. to set burning, as a candle, lamp, fire, match, or cigarette; kindle; ignite.

  2. to turn or switch on (an electric light): One flick of the master switch lights all the lamps in the room.

  1. to give light to; furnish with light or illumination: The room is lighted by two large chandeliers.

  2. to make (an area or object) bright with or as if with light (often followed by up): Hundreds of candles lighted up the ballroom.

  3. to cause (the face, surroundings, etc.) to brighten, especially with joy, animation, or the like (often followed by up): A smile lit up her face. Her presence lighted up the room.

  4. to guide or conduct with a light: a candle to light you to bed.

verb (used without object),light·ed or lit, light·ing.
  1. to take fire or become kindled: The damp wood refused to light.

  2. to ignite a cigar, cigarette, or pipe for purposes of smoking (usually followed by up): He took out a pipe and lighted up before speaking.

  1. to become illuminated when switched on: This table lamp won't light.

  2. to become bright, as with light or color (often followed by up): The sky lights up at sunset.

  3. to brighten with animation or joy, as the face or eyes (often followed by up).

Idioms about light

  1. bring to light, to discover or reveal: The excavations brought to light the remnants of an ancient civilization.

  2. come to light, to be discovered or revealed: Some previously undiscovered letters have lately come to light.

  1. hide one's light under a bushel, to conceal or suppress one's talents or successes.

  2. in a good / bad light, under favorable (or unfavorable) circumstances: She worshiped him, but then she'd only seen him in a good light.

  3. in (the) light of, taking into account; because of; considering: It was necessary to review the decision in the light of recent developments.

  4. light at the end of the tunnel, a prospect of success, relief, or redemption: We haven't solved the problem yet, but we're beginning to see light at the end of the tunnel.

  5. see the light,

    • to come into existence or being.

    • to be made public.

    • to begin to accept or understand a point of view one formerly opposed: Her father was opposed to her attending an out-of-town college, but he finally saw the light.

  6. shed / throw light on, to clarify; clear up: His deathbed confession threw light on a mystery of long standing.

Origin of light

First recorded before 900; (noun and adjective) Middle English; Old English lēoht; cognate with Old Saxon lioht, Old Frisian liacht, Dutch, German licht, Gothic liuhath (noun); akin to Old Norse ljōs (noun), ljōss (adjective), Latin lūx (noun), Greek leukós “bright, white”; (verb) Middle English lighten, Old English līhtan, cognate with Old Saxon liuhtian, Old High German liuhten (German leuchten ), Gothic liuhtjan

Other words from light

  • lightful, adjective
  • light·ful·ly, adverb

Words Nearby light

Other definitions for light (2 of 3)

[ lahyt ]

adjective,light·er, light·est.
  1. of little weight; not heavy: a light load.

  2. of little weight in proportion to bulk; of low specific gravity: a light metal.

  1. of less than the usual or average weight: light clothing.

  2. weighing less than the proper or standard amount: to be caught using light weights in trade.

  3. of small amount, force, intensity, etc.: light trading on the stock market;a light rain;light sleep.

  4. using or applying little or slight pressure or force: The child petted the puppy with light, gentle strokes.

  5. not distinct; faint: The writing on the page had become light and hard to read.

  6. easy to endure, deal with, or perform; not difficult or burdensome: light duties.

  7. not very profound or serious; amusing or entertaining: light reading.

  8. of little importance or consequence; trivial: The loss of his job was no light matter.

  9. easily digested: light food.

  10. low in any substance, as sugar, starch, or tars, that is considered harmful or undesirable: light cigarettes.

  11. (of alcoholic beverages)

    • not heavy or strong: a light apéritif.

    • (especially of beer and wine) having fewer calories and usually a lower alcohol content than the standard product.

  12. spongy or well-leavened, as cake.

  13. (of soil) containing much sand; porous or crumbly.

  14. slender or delicate in form or appearance: a light, graceful figure.

  15. airy or buoyant in movement: When she dances, she's as light as a feather.

  16. nimble or agile: light on one's feet.

  17. free from trouble, sorrow, or worry; carefree: a light heart.

  18. cheerful; merry: a light laugh.

  19. characterized by lack of proper seriousness; frivolous: light conduct.

  20. sexually promiscuous; loose.

  21. easily swayed; changeable: volatile: a heart light of love;His is a life of a man light of purpose.

  22. slightly delirious; dizzy: I get light on one martini.

  23. Military. lightly armed or equipped: light cavalry.

  24. having little or no cargo, encumbrance, or the like; not burdened: a light freighter drawing little water.

  25. adapted by small weight or slight build for small loads or swift movement: The grocer bought a light truck for deliveries.

  26. using small-scale machinery primarily for the production of consumer goods: light industry.

  27. Nautical. noting any sail of light canvas set only in moderate or calm weather, as a royal, skysail, studdingsail, gaff topsail, or spinnaker.

  28. Meteorology. (of wind) having a speed up to 7 miles per hour (3 meters per second).: Compare light air, light breeze.

  29. Phonetics. (of l-sounds) resembling a front vowel in quality; clear: French l is lighter than English l.

  30. Prosody. (of a syllable)

  31. Poker. being in debt to the pot: He's a dollar light.

adverb,light·er, light·est.
  1. with few or no suitcases; lightly: to travel light.

  2. with no load or cargo hauled or carried: a locomotive running light to its roundhouse.

  1. a light product, as a beer or cigarette.

Origin of light

First recorded before 900; Middle English; Old English lēoht, līht; cognate with Old Frisian li(u)cht, Old Saxon -līht, Dutch licht, German leicht, Old Norse lēttr, Gothic leihts

Other words for light

Opposites for light

Other definitions for light (3 of 3)

[ lahyt ]

verb (used without object),light·ed or lit, light·ing.
  1. to get down or descend, as from a horse or a vehicle: As she lighted, the journalists began shouting questions at her.

  2. to come to rest, as on a spot or thing; fall or settle upon; land: The bird lighted on the branch. My eye lighted on some friends in the crowd.

  1. to come by chance; happen; hit (usually followed by on or upon): to light on a clue; to light on an ideal picnic spot.

  2. to fall, as a stroke, weapon, vengeance, or choice, on a place or person: The choice lighted upon our candidate.

Verb Phrases
  1. light into, Informal. to make a vigorous physical or verbal attack on: He would light into anyone with the slightest provocation.

  2. light out, Informal. to leave quickly; depart hurriedly: He lit out of here as fast as his legs would carry him.

Origin of light

First recorded before 900; Middle English lihten, Old English līhtan “to make light, relieve of a weight”; see light2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use light in a sentence

British Dictionary definitions for light (1 of 3)


/ (laɪt) /

  1. the medium of illumination that makes sight possible

  2. Also called: visible radiation electromagnetic radiation that is capable of causing a visual sensation and has wavelengths from about 380 to about 780 nanometres

  1. (not in technical usage) electromagnetic radiation that has a wavelength outside this range, esp ultraviolet radiation: ultraviolet light

  2. the sensation experienced when electromagnetic radiation within the visible spectrum falls on the retina of the eye: Related prefix: photo-

  3. anything that illuminates, such as a lamp or candle

  4. a particular quality or type of light: a good light for reading

    • illumination from the sun during the day; daylight

    • the time this appears; daybreak; dawn

  5. anything that allows the entrance of light, such as a window or compartment of a window

  6. the condition of being visible or known (esp in the phrases bring or come to light)

  7. an aspect or view: he saw it in a different light

  8. mental understanding or spiritual insight

  9. a person considered to be an authority or leader

  10. brightness of countenance, esp a sparkle in the eyes

    • the act of igniting or kindling something, such as a cigarette

    • something that ignites or kindles, esp in a specified manner, such as a spark or flame

    • something used for igniting or kindling, such as a match

    • the effect of illumination on objects or scenes, as created in a picture

    • an area of brightness in a picture, as opposed to shade

  11. a poetic or archaic word for eyesight

  12. the answer to a clue in a crossword

  13. in light of or in the light of in view of; taking into account; considering

  14. light at the end of the tunnel hope for the ending of a difficult or unpleasant situation

  15. out like a light quickly asleep or unconscious

  16. see the light

    • to gain sudden insight into or understanding of something

    • to experience a religious conversion

  17. see the light or see the light of day

    • to come into being

    • to come to public notice

  18. shed light on or throw light on to clarify or supply additional information on

  19. stand in a person's light to stand so as to obscure a person's vision

  20. strike a light

    • (verb) to ignite something, esp a match, by friction

    • (interjection) British an exclamation of surprise

  1. full of light; well-lighted

  2. (of a colour) reflecting or transmitting a large amount of light: light yellow Compare medium (def. 2), dark (def. 2)

  1. phonetics relating to or denoting an (l) pronounced with front vowel resonance; clear: the French "l" is much lighter than that of English See dark (def. 9)

verblights, lighting, lighted or lit (lɪt)
  1. to ignite or cause to ignite

  2. (often foll by up) to illuminate or cause to illuminate

  1. to make or become cheerful or animated

  2. (tr) to guide or lead by light

Origin of light

Old English lēoht; related to Old High German lioht, Gothic liuhath, Latin lux

Derived forms of light

  • lightish, adjective
  • lightless, adjective

British Dictionary definitions for light (2 of 3)


/ (laɪt) /

  1. not heavy; weighing relatively little

  2. having relatively low density: magnesium is a light metal

  1. lacking sufficient weight; not agreeing with standard or official weights

  2. not great in degree, intensity, or number: light rain; a light eater

  3. without burdens, difficulties, or problems; easily borne or done: a light heart; light work

  4. graceful, agile, or deft: light fingers

  5. not bulky or clumsy

  6. not serious or profound; entertaining: light verse

  7. without importance or consequence; insignificant: no light matter

  8. frivolous or capricious

  9. loose in morals

  10. dizzy or unclear: a light head

  11. (of bread, cake, etc) spongy or well leavened

  12. easily digested: a light meal

  13. relatively low in alcoholic content: a light wine

  14. (of a soil) having a crumbly texture

  15. (of a vessel, lorry, etc)

    • designed to carry light loads

    • not loaded

  16. carrying light arms or equipment: light infantry

  17. (of an industry) engaged in the production of small consumer goods using light machinery: Compare heavy (def. 10)

  18. aeronautics (of an aircraft) having a maximum take-off weight less than 5670 kilograms (12 500 pounds)

  19. chem (of an oil fraction obtained from coal tar) having a boiling range between about 100° and 210°C

  20. (of a railway) having a narrow gauge, or in some cases a standard gauge with speed or load restrictions not applied to a main line

  21. bridge

    • (of a bid) made on insufficient values

    • (of a player) having failed to take sufficient tricks to make his contract

  22. phonetics prosody (of a syllable, vowel, etc) unaccented or weakly stressed; short: Compare heavy (def. 13) See also light 1 (def. 30)

  23. phonetics the least of three levels of stress in an utterance, in such languages as English

  24. light on informal lacking a sufficient quantity of (something)

  25. make light of to treat as insignificant or trifling

  1. a less common word for lightly

  2. with little equipment, baggage, etc: to travel light

verblights, lighting, lighted or lit (lɪt) (intr)
  1. (esp of birds) to settle or land after flight

  2. to get down from a horse, vehicle, etc

  1. (foll by on or upon) to come upon unexpectedly

  2. to strike or fall on: the choice lighted on me

Origin of light

Old English lēoht; related to Dutch licht, Gothic leihts

Derived forms of light

  • lightish, adjective
  • lightly, adverb
  • lightness, noun

British Dictionary definitions for Light (3 of 3)


/ (laɪt) /

  1. God regarded as a source of illuminating grace and strength

  2. Quakerism short for Inner Light

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for light


[ līt ]

  1. Electromagnetic radiation that can be perceived by the human eye. It is made up of electromagnetic waves with wavelengths between 4 X 10-7 and 7 X 10-7 meters. Light, and all other electromagnetic radiation, travels at a speed of about 299,728 km (185,831 mi) per second in a vacuum. See also photon.

  2. Electromagnetic energy of a wavelength just outside the range the human eye can detect, such as infrared light and ultraviolet light. See Note at electromagnetic radiation.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for light


The type of electromagnetic wave that is visible to the human eye. Visible light runs along a spectrum from the short wavelengths of violet to the longer wavelengths of red. (See photon.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Other Idioms and Phrases with light


In addition to the idioms beginning with light

  • light a fire under
  • light as a feather
  • light at the end of the tunnel
  • light dawned, the
  • lighten up
  • light heart
  • light into
  • lightning never strikes twice in the same place
  • light on
  • light out
  • light up

also see:

  • begin to see daylight (see the light of day)
  • bring to light
  • come to light
  • go light on
  • green light
  • heavy (light) heart
  • hide one's light
  • in a good (bad) light
  • in the cold light of day
  • in the light of
  • lace (light) into
  • leading light
  • make light of
  • many hands make light work
  • once over lightly
  • out cold (like a light)
  • see the light
  • shed light on
  • sweetness and light
  • travel light
  • trip the light fantastic

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.