mountainous

adjective

moun·​tain·​ous ˈmau̇n-tə-nəs 

ˈmau̇nt-nəs

1

: containing many mountains

mountainous wilderness

2

: resembling a mountain : huge

a stormy ocean with mountainous waves

mountainously adverb

mountainousness noun

Synonyms of mountainous

• vast
• huge
• gigantic
• enormous
• giant
• massive
• tremendous
• colossal
• mammoth
• immense
• astronomical
• monumental
• monstrous

Examples of mountainous in a Sentence

the seemingly mountainous obstacles he had to overcome while growing up

Recent Examples on the Web

Mischie’s comedy takes place in a remote, mountainous village in Romania where every one of the inhabitants has applied for government benefits, claiming disabilities of various kinds. —Matthew Carey, Deadline, 7 May 2026

The sheer scale of these works, and the feeling of being surrounded by that mountainous landscape, started giving me some ideas. —Thomas Patier, Artforum, 7 May 2026

The terrain is mountainous, a mix of desert and semidesert plains. —ABC News, 3 May 2026

The terrain is mountainous, a mix of desert and semi-desert plains. —Ope Adetayo, Los Angeles Times, 3 May 2026

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