[ fur-muh-muh nt ]
/ ˈfɜr mə mənt /


the vault of heaven; sky.


Origin of firmament

1250–1300; Middle English < Late Latin firmāmentum sky, Latin: support, prop, stay, equivalent to firmā(re) to strengthen, support (see firm2) + -mentum -ment

Related forms

fir·ma·men·tal [fur-muh-men-tl] /ˌfɜr məˈmɛn tl/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for firmament

British Dictionary definitions for firmament


/ (ˈfɜːməmənt) /


the expanse of the sky; heavens

Derived Forms

firmamental (ˌfɜːməˈmɛntəl), adjective

Word Origin for firmament

C13: from Late Latin firmāmentum sky (considered as fixed above the earth), from Latin: prop, support, from firmāre to make firm 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012