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 scary—Saturday 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
That is before any black hole should have had a chance to grow to such monstrous masses via mergers or ordinary feeding. — Robert Lea, Space.com, 29 Sep. 2026 But Young, under monstrous pressure all day, threw the ball well short of the sticks on one fourth-and-long and then got picked off when his arm got hit on Carolina’s final effort. — Scott Fowler, Charlotte Observer, 27 Sep. 2026 Receiver Drake London, who had six catches for 80 yards in the first two games, had a monstrous nine-catch, 194-yard performance. — Daniel Flick, AJC.com, 25 Sep. 2026 The winning bidder could (after a near-bottomless spend) turn the hotel back into an oligarchical palace, or expand the hotel operation, or restage the monstrous Succession corporate-retreat scene that was filmed here. — Adriane Quinlan, Curbed, 25 Sep. 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 5 Oct. 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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!