filament

noun

fil·​a·​ment ˈfi-lə-mənt How to pronounce filament (audio)
: 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 adjective
filamentous adjective

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Deliveries of double heater draw-texturing spindles, which are mainly used for polyester filaments, grew 80 percent, with 95 percent going to China. Angela Velasquez, Sourcing Journal, 30 June 2025 But a feather’s smallest functional structures, called keratin filaments, go down to the nanometer scale. Ian Rose, Smithsonian Magazine, 10 June 2025 The buckling problem was solved mainly by switching to a wider-diameter and thus sturdier TPU filament – 2.85 mm as opposed to the more common 1.75 mm. Ben Coxworth may 28, New Atlas, 28 May 2025 Molds belong to the kingdom of Fungi and is a specific form of fungi that grow filament structures known as hyphae. Bruce Y. Lee, Forbes.com, 27 Apr. 2025 See All Example Sentences for filament

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

Time Traveler
The first known use of filament was in 1594

Browse Nearby Words

Cite this Entry

“Filament.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/filament. Accessed 12 Jul. 2025.

Kids Definition

filament

noun
fil·​a·​ment ˈfil-ə-mənt How to pronounce filament (audio)
: 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 adjective

Medical Definition

filament

noun
fil·​a·​ment ˈfil-ə-mənt How to pronounce filament (audio)
: 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 adjective

More from Merriam-Webster on filament

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!