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light 1 (līt)
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n.
1. Physics
a. Electromagnetic radiation that is visible, perceivable by the normal human eye as colors between red and violet, having frequencies between 400 terahertz and 790 terahertz and wavelengths between 750 nanometers and 380 nanometers. Also called visible light.
b. Electromagnetic radiation of any frequency or wavelength.
2. The sensation of perceiving light; brightness: a sudden light that made me blink.
3.
a. A source of light, especially a lamp, a lantern, or an electric lighting fixture: Turn out the lights when you leave.
b. The illumination derived from a source of light: by the light of the moon.
c. The particular quantity or quality of such illumination: moved the lamp closer to get better light.
d. The pathway or route of such illumination to a person: You're standing in his light.
4.
a. A source of fire, such as a match or cigarette lighter.
b. A mechanical device that uses illumination as a signal or warning, especially a beacon or traffic signal.
5.
a. Daylight.
b. Dawn; daybreak.
6. Something, such as a window, that admits illumination.
7. Architecture One of two or more openings in a window divided by a mullion or mullions.
8. Something that provides information or clarification: research that produced little new light on the question.
9.
a. A state of awareness or understanding, especially as derived from a particular source: in the light of experience.
b. Public attention; general knowledge: brought the scandal to light.
c. Spiritual awareness; illumination.
10. A way of looking at or considering a matter; an aspect: saw the situation in a different light.
11. Archaic Eyesight.
12. lights One's individual opinions, choices, or standards: acted according to their own lights.
13. A person who inspires or is adored by another: My daughter is the light of my life.
14. A prominent or distinguished person; a luminary: one of the leading lights of the theater.
15. An expression of the eyes: a strange light in her eyes.
16. lights Pieces of laundry that are not dark in color.
17. Light In Quaker doctrine, the guiding spirit or divine presence in each person.
v. light·ed or lit (lĭt), light·ing, lights
v.tr.
1. To set on fire; ignite or kindle: lit the kindling.
2. To cause to give out light; make luminous: lit a lamp.
3. To provide, cover, or fill with light; illuminate: fireworks lighting the sky.
4. To signal, direct, or guide with light: "You'd ... set the lamp in the dormer window to light him home through the storm" (Edith Nesbit).
5. To enliven or animate: A smile lit her face.
v.intr.
1. To start to burn; be ignited or kindled: Green wood does not light easily.
2. To emit light; be lighted: Wait until the indicator lights up.
adj. light·er, light·est
1.
a. Having a greater rather than lesser degree of lightness.
b. Of or being an additive primary color.
2. Characterized by or filled with light; bright: a room that is light when the shutters are open.
3. Not dark in color; fair: light hair and skin.
4. Served with milk or cream. Used of coffee.
Phrasal Verb:
light up
1. To become or cause to become animated or cheerful.
2. To start smoking a cigarette, cigar, or pipe.
Idioms:
cast/shed/throw light on
To provide information about or clarify (something).
in (the) light of
In consideration of; in relationship to.
light a fire under
To urge or move to action.
light at the end of the tunnel
The prospect of success, relief, or escape after strenuous effort.

[Middle English, from Old English lēoht, līht; see leuk- in the Appendix of Indo-European roots.]

Usage Note: Lighted and lit are equally acceptable as past tense and past participle of light. Both forms are also well established as adjectives: a lighted (or lit) candle.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 
fire (fīr)
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n.
1.
a. A rapid, persistent chemical change that releases heat and light and is accompanied by flame, especially the exothermic oxidation of a combustible substance: destruction by fire.
b. A specific instance of this change that destroys something: a house fire.
c. A burning fuel: a cooking fire.
2. Burning intensity of feeling; ardor or enthusiasm: a musical performance that had fire. See Synonyms at passion.
3. Luminosity or brilliance, as of a cut and polished gemstone.
4. Liveliness and vivacity of imagination; brilliance: the fire of an artistic genius.
5. A severe test; a trial or torment: went through fire to become a leader.
6. A fever or bodily inflammation: tormented by the fire in an infected toe.
7.
a. The discharge of firearms or artillery: heard the fire of cannon.
b. The launching of a missile, rocket, or similar ballistic body.
c. Discharged bullets or other projectiles: subjected enemy positions to heavy mortar fire; struck by rifle fire.
8. Intense, repeated attack or criticism: answered the fire from her political critics.
v. fired, fir·ing, fires
v.tr.
1.
a. To cause to burn; ignite or set fire to: fired the enemy's encampment.
b. To illuminate or cause to resemble fire, as in color: The morning sun fired the tops of the trees.
2.
a. To start (a fuel-burning engine or a vehicle with such an engine). Often used with up.
b. To start or tend a fire in: fire a furnace.
3.
a. To arouse the emotions of; make enthusiastic or ardent. Often used with up: demonstrators who were fired up by their sense of injustice.
b. To inspire or arouse (an emotion or the imagination).
4. To bake or dry by heating, as in a kiln: fire pottery.
5.
a. To discharge (a firearm, for example).
b. To detonate (an explosive).
6.
a. To propel (a projectile) from a weapon or launch (a missile): fired several rounds before the gun jammed.
b. Informal To throw or propel with force and speed: fire a ball at a batter; fire a puck at the goal.
c. To utter or direct with insistence: fired questions at the senator.
7. Games To score (a number) in a game or contest: The golfer fired a 35 on the front nine.
8. To end the employment or service of; dismiss. See Synonyms at dismiss.
v.intr.
1. To become ignited; flame up: wet kindling that just wouldn't fire.
2.
a. To shoot a weapon: aimed and fired at the target.
b. To detonate an explosive.
c. To ignite fuel; start: The engine fired right away.
3.
a. To send out a projectile; discharge: The cannons fired for hours.
b. To propel or hurl a projectile: The pitcher wound up and fired.
4. Physiology To generate an electrical impulse. Used of a neuron.
5. To become yellowed or brown before reaching maturity, as grain.
Phrasal Verbs:
fire away Informal
To start to talk or ask questions.
fire off
1. To utter or ask rapidly.
2. To write and send (a letter, for example) in haste.
fire up
1. To cause to be ignited or to produce fire: fire up a cigar; fire up the grill.
2. To cause to become excited or emotional: a speech that fired up the crowd.
3. To bring to activity; start: Fire up the stereo!
Idioms:
between two fires
Being attacked from two sources or sides simultaneously.
on fire
1. Ignited; ablaze.
2. Filled with enthusiasm or excitement.
start/light/build a fire under Slang
To urge or goad to action.
under fire
1. Exposed or subjected to enemy attack.
2. Exposed or subjected to critical attack or censure: an official who was under fire for mismanagement.

[Middle English fir, from Old English fȳr; see paəw in the Appendix of Indo-European roots.]

firea·ble adj.
firer n.

Word History: Indo-European, the protolanguage from which English and many other languages descend, had pairs of words for some very common things, such as water or fire. Typically, one word in the pair was active, animate, and personified; the other, impersonal and neuter in grammatical gender. In the case of the pair of words for "fire," English has descendants of both, one inherited directly from Germanic, the other borrowed from Latin. Fire goes back to the neuter member of the pair. In Old English "fire" was fȳr, from Germanic *fūr. The Indo-European form behind *fūr is *pūr, whence also the Greek neuter noun pūr, the source of the prefix pyro-. The other Indo-European word for fire appears in ignite, derived from the Latin word for fire, ignis, from Indo-European *egnis. The Russian word for fire, ogon' (stem form ogn-), and the Sanskrit agni-, "fire" (deified as Agni, the god of fire), also come from *egnis, the active, animate, and personified word for fire.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.