To lurk means to wait or move around quietly in a hidden way, usually watching without being noticed. A cat might lurk behind a bush, waiting for the perfect moment to pounce on a toy. In a mystery novel, a suspicious character might lurk in the shadows of an alley, making readers wonder what they're up to.

The word carries a sneaky feeling. When someone lurks, they stay concealed on purpose, often watching or listening while remaining hidden. You might lurk outside the kitchen when you smell cookies baking, hoping to grab one fresh from the oven. A predator lurks near a watering hole, waiting for prey to arrive.

Online, lurking means reading posts or watching conversations without joining in. Someone who lurks in a chat room or on a message board reads everything but never comments or posts. This kind of lurking isn't necessarily bad: many people lurk to learn about a community before deciding to participate.

The word can describe actual hiding or a feeling that something hidden is nearby. You might say danger lurks around the corner or that doubt lurks in someone's mind, meaning these things are present but not obvious.