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

The two nuclear-armed rivals have fought three wars over the mountainous territory that is divided by a de-facto border called the Line of Control. —Tom Rogers, MSNBC Newsweek, 30 Apr. 2025

So Cordero set out to make a video game about it from the perspective of a child in Quito, Ecuador’s mountainous capital. —Lewis Gordon, New York Times, 30 Apr. 2025

The two nuclear-armed rivals have fought three wars over the mountainous territory that is now divided by a de-facto border called the Line of Control since their independence from Britain nearly 80 years ago. —Rhea Mogul, CNN Money, 29 Apr. 2025

The Fox, represents intelligence, agility, and connection to Sinner’s South Tyrol, Italy roots, a mountainous region. —Merlisa Lawrence Corbett, Forbes.com, 29 Apr. 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