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Synonyms

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.


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.


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

"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

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

"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

Other Word Forms

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."

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Reflecting his deep interest in religion and spirituality, above the door is inscribed the prayer: "Lighten our darkness, we beseech thee, O Lord."

From BBC • Jan. 28, 2026

After a generation of baby boomer children hiding under school desks frightened by bomb scares, "Stripes" rolled its eyes and said, "Lighten up, Francis."

From Salon • Feb. 16, 2022

"I was working out on the bench press with my earbuds in, when one of my Future Sailors ran up to me with a scared look on his face, yelling franticly," Lighten told the NTAGS.

From Fox News • Jan. 26, 2022

“You’re digging up the dead. You’re carrying a cemetery on your shoulders … Lighten up,” Duarte snapped at her interviewers, dismissing critics as a “shouty minority”.

From The Guardian • May 12, 2020

“They do that wherever they are. Lighten up. I’ll see you at five.”

From "Tangerine" by Edward Bloor