Fibrous describes something made of or containing fibers, which are thin, thread-like strands that run through a material. When you bite into celery and feel those stringy bits between your teeth, that's because celery is fibrous. When you tear a piece of paper and see tiny threads along the ripped edge, you're seeing the fibrous structure that holds paper together.

Many natural materials are fibrous. Wood is made of long fibers that run along the grain, which is why it splits more easily in one direction than another. Your muscles are fibrous, built from bundles of tiny fibers that contract and relax. Even clouds can look fibrous when they stretch across the sky in wispy strands.

Fibrous materials often share certain qualities: they tend to be tough, they might fray or pull apart in strands, and they're frequently strong in one direction. Cotton is fibrous, which is why it makes such durable fabric. A fibrous rope can support heavy weight because all those fibers work together.

When describing food, fibrous usually means it contains tough strands that require extra chewing, like mango or pineapple. Doctors talk about fibrous foods being helpful for digestion because fiber helps your body process food properly.