Synonyms of monstrous
1
: having extraordinary often overwhelming size : gigantic
… stuffing a monstrous sandwich down his throat.Mike Flaherty
a monstrous skyscraper
2
a
: extraordinarily ugly or vicious : horrible
a monstrous crime
monstrous mayhem
b
: shockingly wrong or ridiculous
This legend assumed monstrous proportions …Louis Untermeyer
a monstrous miscalculation
3
: deviating greatly from the natural form or character : abnormal
a monstrous melon
4
: very great
used as an intensive
… a monstrous hammering on his door.G. D. Brown
a monstrous hangover
5
a
: having the qualities or appearance of a monster
… came face to face with a monstrous creature.Lester David
b
obsolete : teeming with monsters
6
obsolete : strange, unnatural
monstrously adverb
monstrousness noun

monstrous

2 of 3

adverb

chiefly dialectal
: very, extremely
… a monstrous long raft …Mark Twain

monstrousness

3 of 3

noun

mon·​strous·​ness
plural -es
: the quality or state of being monstrous
the monstrousness of the man he plays is kept in bounds—he is scary, but not too scarySaturday Review
Choose the Right Synonym for monstrous

monstrous, prodigious, tremendous, stupendous mean extremely impressive.

monstrous implies a departure from the normal (as in size, form, or character) and often carries suggestions of deformity, ugliness, or fabulousness.

the monstrous waste of the project

prodigious suggests a marvelousness exceeding belief, usually in something felt as going far beyond a previous maximum (as of goodness, greatness, intensity, or size).

made a prodigious effort and rolled the stone aside

tremendous may imply a power to terrify or inspire awe.

the tremendous roar of the cataract

stupendous implies a power to stun or astound, usually because of size, numbers, complexity, or greatness beyond description.

a stupendous volcanic eruption

Examples of monstrous in a Sentence

Adjective It was monstrous of him to keep the truth from them all those years. a monstrous melon that was clearly not fit to eat Adverb a monstrous pretty gal, she was
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
But unlike David, this monstrous trio is designed to indiscriminately kill anyone and everyone in their path. Brian Davids, HollywoodReporter, 8 Sep. 2026 Master of jump scares Zach Cregger, hot off the monstrous success of last year’s Weapons, directs. A.a. Dowd, Vulture, 8 Sep. 2026 Both seem like two ways to, if not be monstrous, then at least refuse to play the game in the way a young interviewer would expect an older, more august person to play along. Merve Emre, The New York Review of Books, 1 Sep. 2026 Lee Becker is transforming into something monstrous and tentacled at night. Jennifer Maas, Variety, 31 Aug. 2026 See All Example Sentences for monstrous

Word History

First Known Use

Adjective

15th century, in the meaning defined at sense 6

Adverb

1569, in the meaning defined above

Time Traveler
The first known use of monstrous was in the 15th century

Browse Nearby Words

Cite this Entry

“Monstrous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/monstrous. Accessed 11 Sep. 2026.

Kids Definition

monstrous

adjective
mon·​strous
ˈmän(t)-strəs
1
: unusually large : gigantic
2
: very ugly or vicious : horrible
3
: shockingly wrong or ridiculous
4
: very different from the usual form : abnormal
monstrously adverb
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