lighten

¹ American  

[lahyt-n] / ˈlaɪt n /

verb (used without object)

1. to become lighter or less dark; brighten.

   The sky lightened after the storm.

2. to brighten or light up, as the eyes or features.

   Her face lightened when she heard the good news.

3. to flash as or like lightning (often used impersonally with it as subject).

   It thundered and lightened for hours.

4. Archaic. to shine, gleam, or be bright.

   steel blades lightening in the sun.

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verb (used with object)

1. to give light to; illuminate.

   A full moon lightened the road.

2. to brighten (the eyes, features, etc.).

   A large smile lightened his face.

3. to make lighter or less dark.

   Add white to lighten the paint.

4. Obsolete. enlighten.

5. Obsolete. to flash or emit like lightning (usually followed by out, forth, ordown ).

   eyes that lightened forth implacable hatred.

lighten ² American  

[lahyt-n] / ˈlaɪt n /

verb (used with object)

1. to make lighter in weight.

   to lighten the load on a truck.

2. to lessen the load of or upon.

   to lighten a cargo ship.

3. to make less burdensome or oppressive; alleviate; mitigate.

   to lighten taxes;

   to lighten someone's cares.

   Synonyms:

   reduce, lessen, ease

   Antonyms:

   aggravate

4. to cheer or gladden.

   Such news lightens my heart.

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verb (used without object)

1. to become less severe, stringent, or harsh; ease up.

   Border inspections have lightened recently.

2. to become less heavy, cumbersome, burdensome, oppressive, etc..

   His worries seem to have lightened somewhat.

3. to become less gloomy; perk up.

   People's spirits usually lighten when spring arrives.

lighten ¹ British  

/ ˈlaɪtən /

verb

1. to become or make light

2. (intr) to shine; glow

3. (intr) (of lightning) to flash

4. (tr) an archaic word for enlighten

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lighten ² British  

/ ˈlaɪtən /

verb

1. to make or become less heavy

2. to make or become less burdensome or oppressive; mitigate

3. to make or become more cheerful or lively

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Other Word Forms

• lightener
  noun

Etymology

Origin of lighten¹

First recorded in 1300–50; Middle English lightnen; see origin at light ¹, -en ¹

Origin of lighten²

First recorded in 1350–1400; Middle English lightnen; see origin at light ², -en ¹

Explanation

To lighten something is to make it brighter or shine a light on it. You can lighten your dark basement room with plenty of lamps and a coat of white paint. Besides "make lighter or illuminate," another meaning of lighten is "make lighter in weight." So you can lighten your load by taking all the heavy books out of your backpack. Figuratively, "to lighten" is to be more cheerful or relaxed, as in: "She decided to lighten the somber mood in the room by telling a few of her funniest knock-knock jokes."

Example Sentences

That isn’t to say that trading activity doesn’t lighten up during the summer months.

From MarketWatch • Apr. 29, 2026

If individual investors and large institutions collectively decide to lighten up on their dollars, it will leave a mark.

From Barron's • Feb. 19, 2026

And then, as the sky starts to lighten ahead of sunrise, we hear footsteps.

From BBC • Dec. 28, 2025

Or did the embrace of “Rocky” and “Jaws” mean that audiences wanted their movies to lighten up?

From The Wall Street Journal • Dec. 18, 2025

The glasses lighten and turn clear, so that I can see the inside of the plane again.

From "Warcross" by Marie Lu

Related Words

• alleviate
• ameliorate
• cut down
• dilute
• ease
• facilitate
• lessen
• mitigate
• mollify
• relieve