filament

American  

[fil-uh-muhnt] / ˈfɪl ə mənt /

noun

1. a very fine thread or threadlike structure; a fiber or fibril.

   filaments of gold.

2. a single fibril of natural or synthetic textile fiber, of indefinite length, sometimes several miles long.

3. a long slender cell or series of attached cells, as in some algae and fungi.

4. Botany. the stalklike portion of a stamen, supporting the anther.

5. Ornithology. the barb of a down feather.

6. (in a light bulb or other incandescent lamp) the threadlike conductor, often of tungsten, in the bulb that is heated to incandescence by the passage of current.

7. Electronics. the heating element (sometimes also acting as a cathode) of a vacuum tube, resembling the filament in an incandescent bulb.

8. Astronomy. a solar prominence, as viewed within the sun's limb.

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filament British  

/ -trɪ, ˌfɪləˈmɛntərɪ, ˈfɪləmənt /

noun

1. the thin wire, usually tungsten, inside a light bulb that emits light when heated to incandescence by an electric current

2. electronics a high-resistance wire or ribbon, forming the cathode in some valves

3. a single strand of a natural or synthetic fibre; fibril

4. botany

   1. the stalk of a stamen

   2. any of the long slender chains of cells into which some algae and fungi are divided

5. ornithol the barb of a down feather

6. anatomy any slender structure or part, such as the tail of a spermatozoon; filum

7. astronomy

   1. a long structure of relatively cool material in the solar corona

   2. a long large-scale cluster of galaxies

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filament Scientific  

/ fĭl′ə-mənt /

1. A fine or slender thread, wire, or fiber.

2. The part of a stamen that supports the anther of a flower; the stalk of a stamen.

3. See more at flower

4. 1. A fine wire that gives off radiation when an electric current is passed through it, usually to provide light, as in an incandescent bulb, or to provide heat, as in a vacuum tube.

   2. A wire that acts as the cathode in some electron tubes when it is heated with an electric current.

5. Any of the dark, sinuous lines visible through certain filters on the disk of the Sun. Filaments are solar prominences that are viewed against the solar surface rather than being silhouetted along the outer edges of the disk.

6. See more at prominence

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Other Word Forms

• filamentary
  adjective
• filamented
  adjective

Etymology

Origin of filament

1585–95; < New Latin fīlāmentum, equivalent to Late Latin fīlā ( re ) to wind thread, spin ( see file ¹) + Latin -mentum -ment

Explanation

The stamen of a flower — the part that produces pollen — consists of a slender stalk, called a filament and an anther. The filament supports the anther, which is where pollen develops. The word filament is from the Latin word filum, which means "thread." Filament, in fact, can be a synonym for thread. In an incandescent light bulb, a fine wire called a filament is heated to high temperatures in a bulb that lacks oxygen to prevent the filament from catching fire as it is heated. The filament begins to glow and gives off light. The first filaments were made from carbon, now they are usually made from tungsten because of its high melting point.

Example Sentences

“This is no longer just his job,” said Tony Haile, chief executive of invitation-only online networking platform Filament.

From The Wall Street Journal • Dec. 19, 2025

The new Philips Hue White Ambiance Filament bulb adds tunable white light, so you can adjust from warm to cool white light.

From The Verge • Sep. 1, 2022

Ryan Gall, Vice President of Filament, the company behind the visuals fans at the show saw, says it took months of planning, and at first, they didn’t even know what they were gearing up for.

From Forbes • Jul. 10, 2015

The team that put on the Fare Thee Well shows brought in Filament, a company that specializes in directing and shooting concerts for some of the biggest acts in the world.

From Forbes • Jul. 10, 2015

PISTILLUM: Germen below the Calyx, round, smooth, and green; Style filiform, white, length of the Filament; Stigma forming a small villous head, fig.

From The Botanical Magazine Vol. 8 Or, Flower-Garden Displayed by Curtis, William

Related Words

• fiber
• thread