fibre

fibre — noun

1. one of the thin strands that plants, animals, or manufactured materials are made

1.nounB1
Definition

one of the thin strands that plants, animals, or manufactured materials are made of, especially strands that can be twisted into cloth

Example

Christopher prefers shirts made from natural fibres like cotton or linen.

collocation: natural fibres

The bamboo stem contains strong fibres that workers use to make furniture.

Common collocations
  • natural fibre
  • synthetic fibre
  • plant fibre
  • cotton fibre
  • bamboo fibre
  • fibre content
Synonyms
  • thread

    a very thin strand, often used for sewing; more specific than fibre

  • strand

    a single thin piece of something, often used for hair or wire

  • filament

    a very fine thread or fibre, used in technical or scientific contexts

Grammar Patterns

countable: a [type] fibre / [plural] fibres

uncountable: [material] fibre

Usage Note

This is the British English spelling; American English uses 'fiber'. For the uncountable sense (material type), do not place 'a' before it: 'cotton fibre' not 'a cotton fibre'.

Common Mistakes

The shirt is made from a cotton fibre.
The shirt is made from cotton fibre.
When referring to the material in general, fibre is uncountable.

2. material made of many thin strands, usually in a loose or fluffy mass, that is r

2.nounB1
Definition

material made of many thin strands, usually in a loose or fluffy mass, that is ready to be prepared into finished items like fabric, rope, or paper

Example

The factory imports raw fibre from several countries and spins it into yarn.

collocation: raw fibre

Once the fibre is cleaned and combed, machines twist it into strong thread.

Common collocations
  • raw fibre
  • synthetic fibre
  • natural fibre
  • fibre production
  • fibre industry
Synonyms
  • material

    more general; fibre emphasises the strand-like nature

  • yarn

    fibres that have already been twisted together; fibre is the pre-twist stage

Grammar Patterns

uncountable: [type] fibre

modifier: fibre [noun]

3. any of the slender, thread-shaped cells that form living tissue in the body, inc

3.nounB2
Definition

any of the slender, thread-shaped cells that form living tissue in the body, including the ones inside muscles, nerves, and organs

Example

Muscle fibres contract when you lift something heavy, helping your arms move.

collocation: muscle fibres

Doctors examined the nerve fibres in Salma's hand to find the cause of the numbness.

collocation: nerve fibres

Common collocations
  • muscle fibre
  • nerve fibre
  • collagen fibre
  • elastic fibre
Synonyms
  • cell

    the basic unit of living tissue; a fibre is a specific type of elongated cell

  • strand

    informal way to describe a fibre-like structure

Grammar Patterns

countable: [body part] fibre(s)

Usage Note

In medical contexts, 'fibre' in this sense is nearly always countable and often appears in the plural ('muscle fibres', 'nerve fibres'). Do not confuse with 'dietary fibre' (sense 5), which is uncountable.

4. an extremely thin strand of glass or plastic that uses light to carry data acros

4.nounB2
Definition

an extremely thin strand of glass or plastic that uses light to carry data across long distances, forming the backbone of modern phone networks and digital television services

Example

Modern internet connections rely on thin glass fibres that carry light signals.

collocation: glass fibre

A single optical fibre can carry thousands of phone calls at the same time.

collocation: optical fibre

Common collocations
  • optical fibre
  • glass fibre
  • fibre cable
  • fibre network
  • fibre optic
  • fibre broadband
Synonyms
  • fibre optic

    often used as an adjective referring to the technology

  • cable

    a bundle containing multiple fibres, not the individual strand

Grammar Patterns

countable: [number] fibre(s)

modifier: fibre [noun]

Usage Note

Often shortened to 'fibre' in compound terms: 'fibre optic', 'fibre cable', 'fibre broadband'. The phrase 'fibre optics' refers to the technology itself, not the individual strands.

Common Mistakes

The internet uses fibre optical.
The internet uses optical fibre.
The adjective is 'optical', placed before 'fibre'.

5. a substance found in plant-based foods such as fruits, vegetables, beans, and wh

5.nounB1
Definition

a substance found in plant-based foods such as fruits, vegetables, beans, and whole grains that is not broken down during digestion but helps move waste through the bowels and keeps the digestive system healthy

Example

Eating more fruit and vegetables is an easy way to increase your fibre intake.

collocation: fibre intake

Foods high in fibre help keep your digestive system working smoothly.

collocation: high in fibre

Common collocations
  • dietary fibre
  • fibre intake
  • high in fibre
  • rich in fibre
  • soluble fibre
  • insoluble fibre
  • fibre supplement
Synonyms
  • roughage

    an older, informal term for dietary fibre, less common now

  • bulk

    refers to the physical volume fibre adds to digested food

Grammar Patterns

uncountable: [adjective] fibre

high/rich in fibre

source of fibre

Usage Note

Often paired with 'dietary' in formal or nutritional contexts, but 'fibre' alone is common in everyday speech ('eat more fibre'). This sense is always uncountable — do not say 'a fibre' when referring to dietary fibre.

Common Mistakes

You should eat more fibres for better health.
You should eat more fibre for better health.
Dietary fibre is uncountable; it does not take a plural -s.

6. the inner strength to do what is right and honest, especially when facing pressu

6.nounC1
Definition

the inner strength to do what is right and honest, especially when facing pressure, temptation, or difficult choices

Example

It takes moral fibre to admit you were wrong in front of a large group.

collocation: moral fibre

Asher showed real fibre by refusing the bribe even though he needed the money.

Common collocations
  • moral fibre
  • inner fibre
  • real fibre
Synonyms
Antonyms

Grammar Patterns

uncountable: moral fibre

show/have/lack moral fibre

Usage Note

This sense is almost always used with 'moral' (moral fibre) or directly modified ('inner fibre', 'real fibre'). It is always uncountable and describes a person's character, not a physical substance.

Common Mistakes

She has a strong fibre.
She has strong moral fibre.
The word 'moral' (or a similar modifier) is almost always needed in this sense.

Word family

  • fibrous
    adjectiveB2
  • fibreglass
    nounB2
  • fibroid
    nounC1
  • fibrositis
    nounC2
  • fibreless
    adjectiveC2

Synonym discussion

Sense: noun/1

These words all refer to thin, long pieces of material, but they differ in use. 'Fibre' is the broadest term, covering natural (cotton, wool) and manufactured (nylon, glass) materials, often with an emphasis on structure and composition. 'Thread' is a fibre that has been twisted or prepared for sewing — it is thinner and more deliberately crafted than raw fibre. 'Strand' describes a single piece within a group, such as a strand of hair or a strand of wire; it can be used for both natural and man-made items but does not carry the material-composition nuance of 'fibre'. 'Filament' is a very fine fibre, often used in technical or scientific contexts, like the thin wire inside a light bulb or the fibrous structures in plants. For example, a cotton plant produces fibre; that fibre is spun into thread; a single strand of that thread is pulled apart in science class to show its filaments.

fibre ↗thread ↗strand ↗filament

Common collocations

Nouns

  • strand of fibre
  • type of fibre
  • source of fibre

Prepositions

  • fibre in [food/plant]
  • fibre from [source]

Etymology

LatinFrenchEnglish

The word 'fibre' comes from Latin 'fibra', meaning 'a thread or filament'. It entered Middle English through Old French 'fibre' during the 14th century. The figurative sense of 'strength of character' (moral fibre) developed in the 1800s. The spelling 'fibre' follows British English conventions, while American English uses 'fiber'. The dietary sense became common in the mid-20th century as nutrition science advanced.