mountainous

adjective

moun·​tain·​ous ˈmau̇n-tə-nəs 

ˈmau̇nt-nəs

1

: containing many mountains

2

: resembling a mountain : huge

mountainously adverb

mountainousness noun

Synonyms

• astronomical
• astronomic
• Brobdingnagian
• bumper
• colossal
• cosmic
• cosmical
• cyclopean
• elephantine
• enormous
• galactic
• gargantuan
• giant
• gigantesque
• gigantic
• grand
• herculean
• heroic
• heroical
• Himalayan
• huge
• humongous
• humungous
• immense
• jumbo
• king-size
• king-sized
• leviathan
• mammoth
• massive
• mega
• mighty
• monster
• monstrous
• monumental
• oceanic
• pharaonic
• planetary
• prodigious
• super
• super-duper
• supersize
• supersized
• titanic
• tremendous
• vast
• vasty
• walloping
• whacking
• whopping

Examples of mountainous in a Sentence

the seemingly mountainous obstacles he had to overcome while growing up

Recent Examples on the Web

Blowing snow, whiteout conditions, and icy roads will make driving treacherous, especially in mountainous regions and along highways. —Josh Hammer, Newsweek, 15 Feb. 2025

Amid a mountainous landscape, described by Coronado and Landin as great for location scouting, the city has been at the mercy of Mexican/American relations for centuries. —Alison Foreman, IndieWire, 13 Feb. 2025

In this mountainous region, spring temperatures will be slightly warmer than usual; precipitation will range from slightly above average to average. —Mike Snider, USA TODAY, 31 Jan. 2025

The area, as well as other mountainous areas north of Los Angeles, was forecast to get six inches to a foot of snow. —Bill Hutchinson, ABC News, 27 Jan. 2025

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

Kids Definition

mountainous

adjective

moun·​tain·​ous ˈmau̇nt-ᵊn-əs 

-nəs

1

: having many mountains

2

: resembling a mountain : huge