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Synonyms

mountainous

American  
[moun-tn-uhs] / ˈmaʊn tn əs /

adjective

  1. abounding in mountains.

    a mountainous wilderness.

  2. of the nature of a mountain.

  3. resembling a mountain or mountains, as being very large and high.

    mountainous waves.


mountainous British  
/ ˈmaʊntɪnəs /

adjective

  1. of or relating to mountains

    a mountainous region

  2. like a mountain, esp in size or impressiveness

"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

Other Word Forms

  • mountainously adverb
  • mountainousness noun
  • nonmountainous adjective
  • nonmountainously adverb
  • semimountainous adjective
  • semimountainously adverb
  • unmountainous adjective

Etymology

Origin of mountainous

First recorded in 1400–50, mountainous is from the late Middle English word mounteynous. See mountain, -ous

Vocabulary lists containing mountainous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Earlier reports suggested the missing crew member might be in the mountainous area of Kohgiluyeh and Boyer-Ahmad province, in the southwestern regions of Iran.

From BBC • Apr. 5, 2026

The airman, an unidentified colonel as we write this, climbed into mountainous terrain despite his injuries to escape detection and await a rescue once the U.S. located him.

From The Wall Street Journal • Apr. 5, 2026

That had sparked a race over the weekend in mountainous terrain, with images posted on social media of US aircraft and helicopters flying low over Iran as part of search-and-rescue operations.

From Barron's • Apr. 5, 2026

The mountainous terrain is rugged and covered by thick bush.

From BBC • Apr. 3, 2026

The Short-Snout has fewer human killings to its name than most dragons, though as it prefers to live in wild and uninhabited mountainous areas, this is not much to its credit.

From "Fantastic Beasts and Where to Find Them" by J.K. Rowling