fiber

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A slender, elongated, threadlike object or structure.
• noun Botany One of the elongated, thick-walled cells that give strength and support to plant tissue.
• noun Any of the filaments constituting the extracellular matrix of connective tissue.
• noun Any of various elongated cells or threadlike structures, especially a muscle fiber or a nerve fiber.
• noun A natural or synthetic filament, as of cotton or nylon, capable of being spun into yarn.
• noun Material made of such filaments.
• noun An essential element of a person's character.
• noun Strength of character; fortitude.
• noun Coarse, indigestible plant matter, consisting primarily of polysaccharides such as cellulose, that when eaten stimulates intestinal peristalsis.

from The Century Dictionary.

• noun The specific name of the beaver, Castor fiber.
• noun [capitalized] A genus of rodents, of the family Muridæ and subfamily Arvicolinæ, of which the type is the muskrat, musquash, or ondatra of North America, Fiber zibethicus, having a long scaly tail, vertically flattened, and large webbed hind feet. See muskrat.
• noun A thread or filament; any fine thread-like part of a substance, as a single natural filament of wool, cotton, silk, or asbestos, one of the slender terminal roots of a plant, a drawn-out thread of glass, etc.
• noun In a collective sense, a filamentous substance; a conglomeration of thread-like tissue, such as exists in animals and plants generally; more generally, any animal, vegetable, or even mineral substance the constituent parts of which may be separated into or used to form threads for textile fabrics or the like: as, muscular or vegetable fiber; the fiber of wool; silk, cotton, or jute fiber; asbestos fiber.
• noun Figuratively, sinew; strength: as, a man of fiber.
• noun Material; stuff; quality; character.
• noun Specifically In anatomy and zoology: A filament; a slender thread-like element, as of muscular or nervous tissue. Most tissues and structures of the body are composed of bundles of fibers. See cut under muscular.
• noun Fibrous tissue in general.
• noun very fine processes passing through and seeming to rivet together several concentric laminæ of bone-tissue; perforating fibers.

from the GNU version of the Collaborative International Dictionary of English.

• noun One of the delicate, threadlike portions of which the tissues of plants and animals are in part constituted.
• noun Any fine, slender thread, or threadlike substance; ; especially, one of the slender rootlets of a plant.
• noun the inherent complex of attributes that determine a person's moral and ethical actions and reactions; sinew; strength; toughness.
• noun A general name for the raw material, such as cotton, flax, hemp, etc., used in textile manufactures.
• noun (Nutrition) that portion of food composed of carbohydrates which are completely or partly indigestible, such as cellulose or pectin; it may be in an insoluble or a soluble form. It provides bulk to the solid waste and stimulates peristalsis in the intestine. It is found especially in grains, fruits, and vegetables. There is some medical evidence which indicates that diets high in fiber reduce the risk of colon cancer and reduce cholesterol levels in the blood. It is also called dietary fiber, roughage, or bulk.
• noun a leatherlike material made by compressing layers of paper or cloth.
• noun a kind of steam gun for converting, wood, straw, etc., into fiber. The material is shut up in the gun with steam, air, or gas at a very high pressure which is afterward relieved suddenly by letting a lid at the muzzle fly open, when the rapid expansion separates the fibers.
• noun (Bot.) plants capable of yielding fiber useful in the arts, as hemp, flax, ramie, agave, etc.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun countable A single elongated piece of a given material, roughly round in cross-section, often twisted with other fibers to form thread.
• noun uncountable A material in the form of fibers.
• noun textiles A material whose length is at least 1000 times its width.
• noun Dietary fiber.
• noun figuratively Moral strength and resolve.
• noun mathematics The preimage of a given point in the range of a map.
• noun computing A kind of lightweight thread of execution.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun coarse, indigestible plant food low in nutrients; its bulk stimulates intestinal peristalsis
• noun any of several elongated, threadlike cells (especially a muscle fiber or a nerve fiber)
• noun a leatherlike material made by compressing layers of paper or cloth
• noun the inherent complex of attributes that determines a persons moral and ethical actions and reactions
• noun a slender and greatly elongated substance capable of being spun into yarn