fibre
Pluralfibres (some meanings)
US spellingfiber
- 1Material made up of long, thin strands, thought of as a mass or substance rather than as single pieces.
The cushions are stuffed with polyester fibre that keeps its shape after washing.
Coconut fibre is woven into tough doormats that last for years.
- 2A long, slender strand of a material, often one of many twisted together to make thread.
Police matched a single fibre from the victim's coat to the boot of the suspect's car.
The wool fibres are washed and combed before they are spun into yarn.
- 3The indigestible part of plant foods such as vegetables, considered as an element of a person's diet.
Wholemeal pasta and lentils are easy ways to get more fibre into your diet.
She switched to a high-fibre breakfast cereal on her GP's advice.
UsageUsually no plural in this meaning: food is high in fibre, a high-fibre diet, and you eat more fibre.
- 4Broadband internet delivered using optical-fibre cables for all or part of the connection to a home or business, or the service providing it.
The village was among the last in the county to get full fibre, and residents can now work from home without dropped video calls.
The small business switched to fibre last year, and uploads that once took hours now finish in minutes.
UsageOften get fibre or switch to fibre; full fibre runs the cable all the way to the home.
- 5Any of the long, thread-like cells or structures found in body tissue, such as muscle cells, nerve axons, or strands of collagen.
A single muscle fibre may contain hundreds of nuclei along its length.
Damaged fibres in the heart muscle are slowly replaced by scar tissue.
Note
In the body the word is used most often of muscle. A skeletal muscle fibre is a single very long cell with many nuclei, formed when many smaller cells fuse during growth. Nerve fibre is looser: it usually names the long extension of a nerve cell together with its sheath, not a whole cell.
Checked 5 Nov 2026 · 3 facts
- A skeletal muscle fibre is a single very long cell. openstax.org
- Skeletal muscle fibres have many nuclei and form through the fusion of smaller cells during development. openstax.org
- A nerve fibre comprises a nerve cell's extension and its sheath, rather than a whole nerve cell. histology.oit.duke.edu
Less common meanings
- 6Inner strength of character, together with the determination to hold firm to what is right.
Critics said the committee lacked the moral fibre to stand up to its wealthiest donors.
Bringing up four children alone after the accident took real moral fibre.
UsageMost often moral fibre, and often with lack: they lacked the moral fibre to act.
Note
A figure drawn from the strands inside a material: what something is made of, all the way through, decides how it holds under strain.
- 7In mathematics, everything in a map's domain that the map sends to one chosen point of its range; in category theory, the pullback of a morphism along a global element.
- 8In computing, a lighter form of thread: a single sequence of a program's instructions that costs less to start and to switch between than an ordinary thread.
Practice
Can you tell the meanings of fibre apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.
Origin
From French fibre, from Old French, from Latin fibra.
Checked 5 Nov 2026 · 2 facts
- English fibre comes from French fibre. en.wiktionary.org
- French fibre comes through Old French from Latin fibra. en.wiktionary.org