lest

"Lest" is a formal, somewhat old-fashioned word that means "for fear that" or "to prevent something from happening." It is used when someone is trying to avoid a bad result. You can think of it as a more formal way of saying "so that something does not happen." You would not usually say, "I locked the door lest burglars come in," in casual conversation; you would more likely say, "I locked the door to keep burglars out." Still, you will often see it in classic literature, legal writing, or formal speeches. It often appears with "should" or with the base form of a verb. For example: "He spoke softly, lest he awaken the baby."

The word "lest" is a formal and somewhat old-fashioned term used to show the purpose of preventing something undesirable. It essentially means "for fear that" or "so that something bad does not happen."

Because of its formal tone, "lest" is rarely used in everyday conversation. Instead, it appears more often in classic literature, poetry, legal writing, and formal public language. It usually introduces a possible negative result that someone wants to avoid. For instance, "She hurried home lest she miss the train" shows that she was worried about missing it and moved faster to prevent that. Similarly, "He kept his opinions to himself, lest they offend anyone," shows a careful effort to avoid causing offense.

Grammatically, "lest" is often followed by the base form of a verb, as in "lest he awaken the baby," or by "should," as in "Take an umbrella, lest it should rain." Both patterns are standard in careful or traditional English. The word may sound a bit literary today, but understanding it helps you notice an important tone of caution and prevention in formal writing.