# filament vs firmament

> English confusable word pair

## The two words

### filament
*noun · IPA /ˈfɪləmənt/ · frequency rank #25,761*
A fine thread or wire.

### firmament
*noun · IPA /ˈfɜːməm(ə)nt/ · frequency rank #48,747*
The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/filament-vs-firmament