noun Chiefly British.




a fine, threadlike piece, as of cotton, jute, or asbestos.
a slender filament: a fiber of platinum.
filaments collectively.
matter or material composed of filaments: a plastic fiber.
something resembling a filament.
an essential character, quality, or strength: people of strong moral fiber.
  1. filamentous matter from the bast tissue or other parts of plants, used for industrial purposes.
  2. a slender, threadlike root of a plant.
  3. a slender, tapered cell which, with like cells, serves to strengthen tissue.
Anatomy, Zoology. a slender, threadlike element or cell, as of nerve, muscle, or connective tissue.
Nutrition. Also called bulk, dietary fiber, roughage.
  1. the structural part of plants and plant products that consists of carbohydrates, as cellulose and pectin, that are wholly or partially indigestible and when eaten stimulate peristalsis in the intestine.
  2. food containing a high amount of such carbohydrates, as whole grains, fruits, and vegetables.
Chemistry. vulcanized fiber.
Optics. optical fiber.
Also especially British, fi·bre.

Origin of fiber

1350–1400; 1970–75 for def 9; Middle English fibre (< Middle French) < Latin fibra filament
Related formsfi·ber·less, adjectivein·ter·fi·ber, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fibre

Contemporary Examples of fibre

  • You will hardly know who I am or what I mean, But I shall be good health to you nevertheless, And filter and fibre your blood.

    The Daily Beast logo
    A Eulogy for Marie Colvin

    Katrina Heron

    March 14, 2012

Historical Examples of fibre

  • I luxuriate in it, I joy in it, I feel it in every fibre of my being.

  • He waited, every nerve and fibre of him tense for her answer.

    The Fortune Hunter

    Louis Joseph Vance

  • It was the trap, ever the trap, the fear of it lurking deep in the life of him, woven into the fibre of him.

    White Fang

    Jack London

  • A kind of universal cramp seized me—a contraction of every fibre of my body.

    Wilfrid Cumbermede

    George MacDonald

  • It is a quality of my fibre, divinely inwoven like mind in matter.

    Cleo The Magnificent

    Louis Zangwill

British Dictionary definitions for fibre


US fiber


a natural or synthetic filament that may be spun into yarn, such as cotton or nylon
cloth or other material made from such yarn
a long fine continuous thread or filament
the structure of any material or substance made of or as if of fibres; texture
essential substance or natureall the fibres of his being were stirred
strength of character (esp in the phrase moral fibre)
  1. a narrow elongated thick-walled cell: a constituent of sclerenchyma tissue
  2. such tissue extracted from flax, hemp, etc, used to make linen, rope, etc
  3. a very small root or twig
anatomy any thread-shaped structure, such as a nerve fibre
Derived Formsfibred or US fibered, adjectivefibreless or US fiberless, adjective

Word Origin for fibre

C14: from Latin fibra filament, entrails



the usual US spelling of fibre
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fibre

chiefly British English spelling of fiber (q.v.); for spelling, see -re.



1530s, from French fibre (14c.), from Latin fibra "a fiber, filament," of uncertain origin, perhaps related to Latin filum "thread," or from root of findere "to split." Fiberboard is from 1897; Fiberglas is 1937, U.S. registered trademark name; and fiber optics is from 1956.

Online Etymology Dictionary, © 2010 Douglas Harper

fibre in Medicine




A slender thread or filament.
Extracellular filamentous structures such as collagenic or elastic connective tissue fibers.
The nerve cell axon with its glial envelope.
An elongated threadlike cell, such as a muscle cell or one of the epithelial cells of the lens of the eye.
Coarse, indigestible plant matter, consisting primarily of polysaccharides such as cellulose, that when eaten stimulates intestinal peristalsis.roughage
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

fibre in Science



The parts of grains, fruits, and vegetables that contain cellulose and are not digested by the body. Fiber helps the intestines absorb water, which increases the bulk of the stool and causes it to move more quickly through the colon.
One of the elongated, thick-walled cells, often occurring in bundles, that give strength and support to tissue in vascular plants. Fibers are one type of sclerenchyma cell.
Any of the elongated cells of skeletal or cardiac muscle, made up of slender threadlike structures called myofibrils.
The axon of a neuron.
Related formsfibrous adjective
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.