mountainous

/ˈmaʊn.tɪ.nəs/

//ˈmaʊn.tɪ.nəs// adj

By · According to Wiktionary data (CC BY-SA) ·

"mountainous" is a 11-letter English headword indexed on PlainSpell.

The verdict

“mountainous” is a moderately-common English word, ranked #17,681 in English word frequency and used as an adjective.

#17,681
frequency rank, English
11
letters
15
tracked misspellings
1
confusable pair

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Having many mountains; characterized by mountains; of the nature of a mountain; rough (terrain); rocky.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

mountainous vs mountains
82% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for mountainous
PropertyValue
Headwordmountainous
LanguageEnglish
Part of speechAdjective
IPA/ˈmaʊn.tɪ.nəs/
Letters11
Frequency rank#17,681
Misspellings tracked15
Confusable pairs1
SourceWiktionary (kaikki.org)

Where “mountainous” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). mountainous lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for mountainous is 11 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as /ˈmaʊn.tɪ.nəs/. Corpus data places it at rank #17,681 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 15 likely wrong-spelling variants for mountainous, with forms such as "mmountainous", "monutainous", and "mounatinous". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 1 confusable-pair relationship, "mountains", since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: From mountain + -ous after Middle French montagneux, from Late Latin montāniōsus, from montānia, from Latin montem (“mountain”). The correct English form is mountainous, spelled M-O-U-N-T-A-I-N-O-U-S.

Definition

  1. 1
    Having many mountains; characterized by mountains; of the nature of a mountain; rough (terrain); rocky.
  2. 2
    Resembling a mountain, especially in size; huge; towering.
  3. 3
    Very difficult.
  4. 4
    Inhabiting mountains; hence, barbarous.

Etymology

From mountain + -ous after Middle French montagneux, from Late Latin montāniōsus, from montānia, from Latin montem (“mountain”).

This word in other languages

montañoso(Español)montagneux(Français)bergig(Deutsch)montanhoso(Português)

Common misspellings

Also misspelled as: mmountainous,monutainous,mounatinous,mounntainous,mountainnous,mountainosu,mountainouss,mountainuos,mountaionus,mountanious,mountianous,mounttainous,moutnainous,muontainous,omuntainous

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of mountainous - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

mmountainous1monutainous2mounatinous2mounntainous1mountainnous1mountainosu2mountainouss1mountainuos2
Edit distance from "mountainous"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "mountainous"?
"mountainous" is spelled M-O-U-N-T-A-I-N-O-U-S. The IPA pronunciation is /ˈmaʊn.tɪ.nəs/.
What does "mountainous" mean?
As an adjective, "mountainous" means: Having many mountains; characterized by mountains; of the nature of a mountain; rough (terrain); rocky.
What words are commonly confused with "mountainous"?
"mountainous" is commonly confused with "mountains". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "mountainous"?
The IPA (International Phonetic Alphabet) transcription for "mountainous" is /ˈmaʊn.tɪ.nəs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "mountainous"?
From mountain + -ous after Middle French montagneux, from Late Latin montāniōsus, from montānia, from Latin montem (“mountain”). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “mountainous”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is M-O-U-N-T-A-I-N-O-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈmaʊn.tɪ.nəs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “mountains” - see the side-by-side comparison. mountainous vs mountains
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list