firmament

American  

[fur-muh-muhnt] / ˈfɜr mə mənt /

noun

1. the vault of heaven; sky.

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firmament British  

/ ˈfɜːməmənt, ˌfɜːməˈmɛntəl /

noun

1. the expanse of the sky; heavens

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Other Word Forms

• firmamental
  adjective

Etymology

Origin of firmament

1250–1300; Middle English < Late Latin firmāmentum sky, Latin: support, prop, stay, equivalent to firmā ( re ) to strengthen, support ( see firm ²) + -mentum -ment

Explanation

The firmament is the curve of the sky, especially if you imagine it as a solid surface. You can describe the sky at night as a firmament shining with stars (if you're feeling poetic). The word firmament comes from the Latin firmus, or "firm," and this description of the sky as something solid reflects ancient ideas of the way the universe was constructed. The first stargazers imagined the sky as a sphere, and it wasn't until the late 1500s that the idea of an infinite universe was seriously considered. Today the word firmament is mostly literary, used to poetically describe the visual curve of the sky.

Example Sentences

By the time police arrived at the home on Firmament Avenue, the suspect or suspects were gone.

From Los Angeles Times • Aug. 8, 2024

Firmament is a canopy net of 21,600 lights which move to classical music.

From The Guardian • Sep. 1, 2016

Perhaps the most beautiful piece to make sure you spend some time experiencing at Burning Man this year is Firmament by Christopher Schardt.

From The Guardian • Sep. 1, 2016

One evening, he recalls in The Firmament of Time, he was accidentally locked in a museum among grotesque skeletons of giant crabs.

From Time Magazine Archive

Thou art Earth, thou art Firmament, and thou art Heaven.

From The Mahabharata of Krishna-Dwaipayana Vyasa, Volume 3 Books 8, 9, 10, 11 and 12 by Ganguli, Kisari Mohan