mountainous

adjective

moun·tain·ous ˈmau̇n-tə-nəs

ˈmau̇nt-nəs

Synonyms of mountainous

: containing many mountains

mountainous wilderness

: resembling a mountain : huge

a stormy ocean with mountainous waves

mountainously adverb

mountainousness noun

Examples of mountainous in a Sentence

the seemingly mountainous obstacles he had to overcome while growing up

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.

In Southern California, the Red Flag Warning for the mountainous areas in Ventura and Los Angeles counties will be in effect from Thursday morning through Friday night. — ABC News, 15 Oct. 2026 Elsewhere, Southern California Edison is considering over 120,000 customer shutoffs between the mountainous areas of Ventura, Los Angeles and San Bernardino. — Sean MacAday, Sacbee.com, 14 Oct. 2026 In Peru’s mountainous southern region, dozens of wildfires have destroyed tens of thousands of acres of land in the past few weeks and left at least five people dead. — Jessica Puckett, Condé Nast Traveler, 14 Oct. 2026 The Houthis are entrenched, battle-hardened and know the mountainous terrain. — Tim Lister, CNN Money, 13 Oct. 2026 See All Example Sentences for mountainous

Word History

Etymology

Middle English mounteynous, borrowed from Anglo-French muntaignus, from muntaigne, mountaigne mountain + -us -ous

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler

The first known use of mountainous was in the 14th century

See more words from the same century

Cite this Entry

Style

“Mountainous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mountainous. Accessed 20 Oct. 2026.

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Kids Definition

mountainous

adjective

moun·tain·ous ˈmau̇nt-ᵊn-əs

-nəs

: having many mountains

: resembling a mountain : huge

mountainous

adjective

Synonyms of mountainous

Examples of mountainous in a Sentence

Word History

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Cite this Entry

Kids Definition

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