fiber

1. (countable) A single elongated piece of a given material, roughly round in cross-section, often twisted with other fibers to form thread.Examples: "The microscope showed a single blue fiber stuck to the sole of the shoe."UScountable

2. (uncountable) A material in the form of fibers.Examples: "The cloth is made from strange, somewhat rough fiber."USuncountable

3. (textiles) A material whose length is at least 1000 times its width.Examples: "Please use polyester fiber for this shirt."UScountableuncountable

4. (figuratively) Moral strength and resolve.Examples: "The ordeal was a test of everyone's fiber."UScountablefigurativelyuncountable

5. (mathematics) The preimage of a given point in the range of a map.Examples: "Under this map, any two values in the fiber of a given point on the circle differ by 2π."UScountableuncountable

6. (category theory) The pullback of a morphism along a global element (called the fiber of the morphism over the global element).UScountableuncountable