n. (US fiber) 1 Biol. any of the threads or filaments forming animal or vegetable tissue and textile substances. 2 a piece of glass in the form of a thread. 3 a a substance formed of fibres. b a substance that can be spun, woven, or felted. 4 the structure, grain, or character of something (lacks moral fibre). 5 dietary material that is resistant to the action of digestive enzymes; roughage. fibre optics optics employing thin glass fibres, usu. for the transmission of light, esp. modulated to carry signals. fibred adj. (also in comb.). fibreless adj. fibriform adj.
[ ME f. F f. L fibra ]