If something is fibrous, it has many thin threads in it, or it looks as if it is made of threads. Doctors use it for the tough, stringy stuff in the body — fibrous tissue that holds parts together, or a fibrous lump that feels thread-like under the fingers. Cooks and food labels use it for plants: celery, mango, and some meat can feel fibrous when you chew, because of those threads. It is a slightly scientific word. In ordinary talk people often say stringy or tough instead, especially about food. Though actually, the famous everyday word is the noun fibre (American spelling fiber) — “eat more fibre” on a cereal box — and fibrous is just the adjective that sits beside it. Fibrous does not always mean “healthy”. A fibrous root or a fibrous scar is about shape and feel, not about breakfast.