Filament

How to spell filament

8 letters · 3 syllables

How to pronounce filament

Say the part in capitals loudest.

What does filament mean?

1. nounA very thin thread, fibre, or wire, such as the coiled wire inside an old light bulb.

Filament in a sentence

• The old bulb stopped working when its filament finally burned out.

• The 3D printer feeds a thin plastic filament through a heated nozzle.

Where does filament come from?

Language of origin: Latin

This word comes from the Latin filamentum, meaning 'a thin thread', which was built on the noun filum, the ordinary Latin word for a thread or string. English took it in around the early 1600s, originally from the scientific Latin used by anatomists and naturalists who needed a precise word for the slender, threadlike structures they were describing. The core sense has stayed remarkably stable: anything long, fine, and threadlike, whether a fibre in a plant, a thread of muscle, or later the glowing wire inside a light bulb. The same filum root threads through several familiar English words, including 'file' (originally a string on which papers were strung) and 'fillet' (a thin strip). Keeping that fil + a + ment structure in mind helps explain the single l and the unstressed middle vowel that trips people up.

How the word is built

• fil (from Latin filum: thread)
• -a- (connecting vowel)
• -ment (noun suffix: result or means)