filament

noun

fil·​a·​ment ˈfi-lə-mənt 

: a single thread or a thin flexible threadlike object, process, or appendage (see appendage sense 2): such as

a

: a tenuous (see tenuous sense 2) conductor (as of carbon or metal) made incandescent by the passage of an electric current

specifically : a cathode (see cathode sense 2) in the form of a metal wire in an electron tube

b(1)

: a thin and fine elongated constituent part of a gill (see gill entry 2 sense 1)

(2)

: an elongated thin series of cells attached one to another or a very long thin cylindrical single cell (as of some algae, fungi, or bacteria)

c

: the anther-bearing stalk of a stamen see flower illustration

filamentary

ˌfi-lə-ˈmen-t(ə-)rē 

adjective

filamentous

ˌfi-lə-ˈmen-təs 

adjective

Synonyms

• bristle
• fiber
• hair
• thread

Examples of filament in a Sentence

algae covered with tiny filaments

the cable was made up of fine filaments twisted together

Recent Examples on the Web

These magnetic forces may be strong enough to counteract the typical gravitational star-forming collapse of molecular clouds, instead confining material into dense filaments seen in the JWST images, which helps explain why Sgr C is forming fewer stars than expected, according to the two new papers. —Sharmila Kuthunur, Space.com, 3 Apr. 2025

Her dress was constructed from a network of branching filaments that create a ghostly, organic silhouette. —Renan Botelho, WWD, 25 Mar. 2025

According to the team, the signals are inconsistent with those previously seen with other types of dense gas filaments, and show no association with dust emission. —Thomas G. Moukawsher, Newsweek, 21 Mar. 2025

The Rauch Satin Sheen Christmas ornament line was born in the 1960s after a call from Bill Spiegel of Spiegel Catalog asking if Rauch’s machines could wind rayon filament onto a foam ball. —Catherine Muccigrosso, Charlotte Observer, 21 Mar. 2025

Word History

Etymology

Middle French, from Medieval Latin filamentum, from Late Latin filare to spin — more at file

First Known Use

1594, in the meaning defined above

Rhymes for filament

• monofilament

Kids Definition

filament

noun

fil·​a·​ment ˈfil-ə-mənt 

: a single thread or a thin flexible threadlike object, process, or part: as

a

: a wire (as in a light bulb) that is made to glow by the passage of an electric current

b

: a long chain of cells (as of some bacteria or algae)

c

: the anther-bearing stalk of a plant stamen

filamentous

ˌfil-ə-ˈment-əs 

adjective

Medical Definition

filament

noun

fil·​a·​ment ˈfil-ə-mənt 

: a single thread or a thin flexible threadlike object, process, or appendage

especially : an elongated thin series of cells attached one to another or a very long thin cylindrical single cell (as of some algae, fungi, or bacteria)

filamentous

ˌfil-ə-ˈment-əs 

adjective