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Synonyms

lest

American  
[lest] / lɛst /

conjunction

  1. for fear that; so that (one) should not (used negatively to introduce a clause expressive of an action or occurrence requiring caution).

    He kept his notes by his side lest faulty memory lead him astray.

  2. that (used after words expressing fear, danger, etc.).

    There was danger lest the plan become known.


idioms

  1. lest we forget. see lest we forget.

lest British  
/ lɛst /

conjunction

  1. so as to prevent any possibility that

    he fled the country lest he be captured and imprisoned

  2. (after verbs or phrases expressing fear, worry, anxiety, etc) for fear that; in case

    he was alarmed lest she should find out

"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

Etymology

Origin of lest

First recorded before 1000; Middle English leste, contraction of the lesse the, thi les the; late Old English the lǣste, earlier thȳ lǣs the, literally, “whereby less that” ( thȳ instrumental case of the demonstrative and relative pronoun, lǣs less, the conjunction)


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.

See Examples For:

Do I want to have to send out a little digital warrior to fight for me every time I want to book a golf tee time, lest there be none left?

From Slate ● Oct. 14, 2026

This is a matinee coffee film, not a popcorn feature, lest anyone expect edge-of-your-seat tension.

From Salon ● Oct. 11, 2026

In Borneo's West Kalimantan province, at lest 15 of the animals have been rescued from flames and haze since July, some stuck in plantations after fires cut off access to their forest home.

From Barron's ● Sep. 11, 2026

Teams are always circumspect about doing anything too exotic during the preseason, lest they give regular-season opponents something to study.

From Los Angeles Times ● Aug. 14, 2026

He tried to sight down along the muzzle, tried to remember to aim low, but was afraid to point down lest he lose the ball again.

From "The Fighting Ground" by Avi

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