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.

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idioms

1. lest we forget. 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

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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

This is one sequel you can’t afford to miss in theaters, lest you incur Miranda Priestly’s infamous wrath.

From Salon

Others avoided mentioning any desire for bodily change, lest the conversation circle back to mindset rather than concrete goals.

From The Wall Street Journal

For much of mankind’s history, mere day-to-day survival has been the real priority — and, lest we forget, it still is for a good part of the planet’s population.

From MarketWatch

“But there needs to be limits, lest drone surveillance becomes pervasive and changes what it’s like to be out in public in America,” he said.

From The Wall Street Journal

It enables Alexander to be briefed and to update his handlers, though he can’t stay in there too long, lest suspicions be aroused on the other side of the hack.

From The Wall Street Journal