lest

Lest means "in order not to" or "so that" something won't happen. It's often used in expressions of caution.

When we use lest, we're warning someone about a possible problem or danger. We might say things like "I'm going to carry an umbrella lest it rains." Here, we're using the umbrella as protection against getting wet. Or "Be quiet lest you wake up the baby," where we want to avoid disturbing the sleeping child. The word can also be used in phrases like "I'll bring a spare tire lest we get a flat one" - here, we're prepared for an emergency. Lest is often used with verbs like "be", "do", or "get", and it's usually followed by a verb ending in -ing (like "rain" or "wake").