mountainous

mountainous — adjective

1. describes a piece of land or a region that is covered with many mountains, so th

1.adjectiveB1
Definition

describes a piece of land or a region that is covered with many mountains, so that the surface is not flat and travel is often difficult

Example

The mountainous region of central Taiwan is home to many indigenous communities.

collocation: mountainous region

Zayd spent three weeks hiking through the mountainous terrain of northern Laos.

collocation: mountainous terrain

Common collocations
  • mountainous region
  • mountainous terrain
  • mountainous landscape
  • mountainous area
  • mountainous road
Synonyms
  • rugged

    focuses on rough, uneven ground rather than specifically many mountains

  • hilly

    similar but describes smaller elevations (hills); milder than mountainous

  • alpine

    specifically relating to high mountains, especially the Alps; more technical

Antonyms
  • flat

    level ground with no mountains or hills

  • level

    even surface without raised features

Grammar Patterns

mountainous + noun

be + mountainous

Usage Note

This sense is used almost exclusively for describing geography — regions, terrain, landscapes, or areas. It does not describe the appearance of a single mountain, but rather a landscape full of many mountains.

Common Mistakes

The mountainous peak was covered in snow.
The mountain peak was covered in snow.
'Mountainous' describes a region with many mountains, not an individual mountain.
This area is very mountain.
This area is very mountainous.
'Mountainous' is the adjective form; 'mountain' is a noun.

2. extremely large in size, amount, or degree, often in a way that is difficult to

2.adjectiveB2
Definition

extremely large in size, amount, or degree, often in a way that is difficult to manage or overwhelming

Example

The national debt has reached mountainous proportions that worry many economists today.

collocation: mountainous proportions

After the floods, the relief team faced the mountainous task of rebuilding homes.

collocation: mountainous task

Common collocations
  • mountainous task
  • mountainous proportions
  • mountainous debt
  • mountainous pile
  • mountainous waves
Synonyms
  • enormous

    more neutral and common; lacks the 'overwhelming' connotation

  • colossal

    suggests impressive or shocking size; slightly more dramatic

  • staggering

    emphasises surprise or disbelief at the size; more emotional

Antonyms

Grammar Patterns

mountainous + noun

Usage Note

This is a figurative sense. Commonly paired with nouns like 'task,' 'debt,' 'proportions,' 'pile,' 'wave,' or 'problem.' It often carries the idea that something feels overwhelming or hard to overcome.

Common Mistakes

He ate a mountainous hamburger for lunch.
He ate an enormous hamburger for lunch.
'Mountainous' is used figuratively for abstract or overwhelming things, not for ordinary large objects.

Word family

  • mountain
    nounA2
  • mountaineer
    nounB2
  • mountaineering
    nounB2
  • mountain bike
    nounB1

Synonym discussion

Sense: adjective/1

All four words describe land that is not flat, but they differ in degree and focus. 'Mountainous' is the broadest term, used for any area covered with many mountains. 'Hilly' describes gentler terrain with smaller, rounded elevations — a county might be hilly without being mountainous. 'Rugged' emphasises rough, uneven, rocky ground; a coastline can be rugged even without mountains. 'Alpine' is the most specific, referring to high-elevation environments like the Alps, with cold temperatures and sparse vegetation. For example: 'The terrain was so mountainous that the team needed climbing gear.' vs. 'A rugged hiking trail followed the coast.' vs. 'Alpine flowers bloom only in the brief summer.'

ruggedhillyalpine ↗

Etymology

LatinOld FrenchEnglish

Mountainous comes from the noun 'mountain' (from Latin 'montanus', meaning 'of a mountain') plus the suffix '-ous', which turns nouns into adjectives meaning 'full of' or 'having the nature of'. The word entered English in the 1400s from Old French 'montagneus'. Its figurative sense — meaning 'huge like a mountain' — developed a few centuries later.