monster

American  

[mon-ster] / ˈmɒn stər /

noun

1. a nonhuman creature so ugly or monstrous as to frighten people.

2. any creature grotesquely deviating from the normal shape, behavior, or character.

3. a person who provokes or elicits horror by wickedness, cruelty, etc.

   Synonyms:

   miscreant, devil, demon, brute, fiend

4. any animal or thing huge in size.

5. a legendary animal combining features of animal and human form or having the forms of various animals in combination, as a centaur, griffin, or sphinx.

6. Biology.

   1. an animal or plant of abnormal form or structure, as from marked malformation or the absence of certain parts or organs.

   2. a grossly anomalous fetus or infant, especially one that is not viable.

7. anything unnatural or monstrous.

---

adjective

1. huge; enormous; monstrous.

   a monster tree.

monster British  

/ ˈmɒnstə /

noun

1. an imaginary beast, such as a centaur, usually made up of various animal or human parts

2. a person, animal, or plant with a marked structural deformity

3. a cruel, wicked, or inhuman person

4. 1. a very large person, animal, or thing

   2. ( as modifier )

      a monster cake

---

verb

1. informal to criticize (a person or group) severely

2. sport to use intimidating tactics against (an opponent)

monster Idioms  

1. see green-eyed monster.

---

Other Word Forms

Derived Forms

• monsterlike
  adjective

Etymology

Origin of monster

First recorded in 1250–1300; Middle English monstre, from Latin mōnstrum “portent, unnatural event, monster,” from mon(ēre) “to warn” + -strum, noun suffix

Explanation

Monsters are imaginary scary creatures that lurk in dark places and horror movies. If it's got 3 heads, shark teeth and lives under your bed, then it's probably a monster. Monsters are big. Monsters are hairy. And monsters are certainly scary. Think of the Abominable Snow Man, that Loch Ness creature, or even Shrek — even though he's technically an ogre. This word isn't only for the imaginary, though: you could call anything freakish, frightening, or particularly evil a monster, like a cruel murderer or even a really big, violent storm.

Example Sentences

It was erected during the final week of April, when one of Trump Doral’s four golf courses—the Blue Monster, famous for its punishing water hazards—hosted the PGA Championship.

From Slate • Jun. 2, 2026

The Official Monster Raving Loony Party has named its leader and co-founder - Alan Hope - otherwise known as Alan "Howlin" Laud Hope.

From BBC • May 19, 2026

And Lady Gaga, Mother Monster though she is, has spent her short but promising acting career channeling grandma, which I mean with the utmost respect and adoration.

From Salon • May 10, 2026

As Fenway prices have soared, the experience commodified into a bucket list item with Green Monster seats and a “Sweet Caroline” singalong, the team’s performance has veered around like a cat driving a Buick.

From The Wall Street Journal • Apr. 27, 2026

“You might want to sing that protection song. I see a lot of hungry eyes looking at you,” Mother Water Monster said.

From "Healer of the Water Monster" by Brian Young

Related Words

• behemoth
• freak
• giant
• whale