monster

1 of 2

noun

mon·​ster ˈmän(t)-stər 

plural monsters

1

a

: an animal of strange or terrifying shape

a mythical monster

a sea monster

… visualize this scaleless monster, eight or nine feet long, sprawling in the shade by the side of the mud pools …

—W. E. Swinton

b

informal : one unusually large for its kind

That truck is a monster.

That's why I was born in my grandmother's house—a grand, brick Federal monster of a house.

—John Irving

2

a

: an animal or plant of abnormal form or structure

b

: one who deviates from normal or acceptable behavior or character

an immoral monster

3

: a threatening force

… the same monster—Destiny … that rolls every civilization to doom …

—W. L. Sullivan

4

: something monstrous

especially : a person of unnatural or extreme ugliness, deformity, wickedness, or cruelty

a cruel monster of a boss

5

: one that is highly successful

That movie was a monster at the box office.

monster

2 of 2

adjective

: enormous or impressive especially in size, extent, or numbers

Synonyms of monster

Noun

• demon
• grotesque
• ogre

Adjective

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

Examples of monster in a Sentence

Noun

That car is a monster.

Inflation has become an economic monster.

Adjective

The movie turned out to be a monster hit.

Recent Examples on the Web

Noun

Peasants whisper about monsters in the forest, and in the interlude between the wars, Lajos gazes at a house that is burning down and has a premonition of the world-historical destruction to come. —Becca Rothfeld, New Yorker, 23 Apr. 2026

For those who didn't watch, Stewart had another monster game last night and is providing protection for Elly De La Cruz, who hit two bombs last night. —Joe Kinsey Outkick, FOXNews.com, 22 Apr. 2026

Adjective

The fourth line had a monster game against the Blue Jackets. —Steve Conroy, Boston Herald, 14 Apr. 2026

Parkinson stands 6-foot-7 and had monster red-zone production in 2025, which would offer a dimension that the Broncos haven’t had at tight end since the days of Julius Thomas. —Luca Evans, Denver Post, 27 Mar. 2026

Word History

Etymology

Noun

Middle English monstre, from Anglo-French, from Latin monstrum omen, monster, from monēre to warn — more at mind

Adjective

from attributive use of monster entry 1

First Known Use

Noun

14th century, in the meaning defined at sense 1a

Adjective

1837, in the meaning defined above

Phrases Containing monster

• Gila monster
• green-eyed monster
• Loch Ness monster
• monster truck
• party monster
• sea monster

Kids Definition

monster

1 of 2 noun

mon·​ster ˈmän(t)-stər 

1

: an animal or plant of abnormal form or structure

2

: a strange or horrible creature

3

: something unusually large

4

: an extremely wicked or cruel person

monster

2 of 2 adjective

: very large : enormous