Nibble means to take very small bites of something, eating it bit by bit. A mouse nibbles on a piece of cheese, taking tiny bites with its small teeth. You might nibble on crackers while doing homework, eating them slowly without really thinking about it.

People often nibble when they're not very hungry, or when they want to make food last longer. At a party, guests might nibble on snacks throughout the evening rather than sitting down for a full meal. Fish nibble at bait on a fishing line, taking such small bites that you can barely feel the tug.

The word suggests delicate, careful eating rather than big, enthusiastic bites. A rabbit nibbles clover in a field. A person nervous about a test might nibble on their pencil eraser without realizing it. When something has been nibbled, you can see the small tooth marks where little pieces were taken away.

As a noun, a nibble is a small bite. In computers, a nibble is also a small unit of data, exactly half the size of a byte (four bits instead of eight). Programmers borrowed the word because it perfectly describes something small but meaningful.