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.

Definitions of monster
  1. noun
    an imaginary creature usually having various human and animal parts
    see moresee less
    show 5 examples...
    hide 5 examples...
    large hairy humanoid creature said to live in wilderness areas of the United States and Canada
    Loch Ness monster
    a large aquatic animal supposed to resemble a serpent or plesiosaur of Loch Ness in Scotland
    (Norse mythology) the Norse dragon that guarded a treasure and was slain by Sigurd
    (Greek mythology) dragon killed by Apollo at Delphi
    (classical mythology) the hideous snake-haired monsters (usually three in number) who pursued unpunished criminals
    show 26 types...
    hide 26 types...
    bogeyman, booger, boogeyman, bugaboo, bugbear
    an imaginary monster used to frighten children
    mythical creature, mythical monster
    a monster renowned in folklore and myth
    legendary creature
    a monster that is unverifiable but popularly accepted as possibly factual
    (classical mythology) a serpent with a head at each end of its body
    (classical mythology) a serpent (or lizard or dragon) able to kill with its breath or glance
    (classical mythology) a mythical being that is half man and half horse
    Cerberus, hellhound
    (Greek mythology) the three-headed dog guarding the entrance to Hades; son of Typhon
    Chimaera, Chimera
    (Greek mythology) fire-breathing female monster with a lion's head and a goat's body and a serpent's tail; daughter of Typhon
    monster hatched by a reptile from a cock's egg; able to kill with a glance
    dragon, firedrake
    a creature of Teutonic mythology; usually represented as breathing fire and having a reptilian body and sometimes wings
    (Greek mythology) a mythical monster with three heads that was slain by Hercules
    (Greek mythology) any of three winged sister monsters and the mortal Medusa who had live snakes for hair; a glance at Medusa turned the beholder to stone
    griffin, griffon, gryphon
    winged monster with the head of an eagle and the body of a lion
    (Greek mythology) vicious winged monster; often depicted as a bird with the head of a woman
    (Greek mythology) monster with nine heads; when struck off each head was replaced by two new ones
    monstrous sea creature symbolizing evil in the Old Testament
    mantichora, manticora, manticore, mantiger
    a mythical monster having the head of man (with horns) and the body of a lion and the tail of a scorpion
    (Greek mythology) a mythical monster with the head of a bull and the body of a man; slain by Theseus
    Nemean lion
    (Greek mythology) an enormous lion strangled by Hercules as the first of his 12 labors
    mythical bird of prey having enormous size and strength
    reptilian creature supposed to live in fire
    (Greek mythology) a riddling winged monster with a woman's head and breast on a lion's body; daughter of Typhon
    (Scandanavian folklore) a supernatural creature (either a dwarf or a giant) that is supposed to live in caves or in the mountains
    (Greek mythology) son of Gaea and Tartarus who created the whirlwinds; had a terrifying voice and 100 dragon heads that spurted fire
    (Greek mythology) a monster with a hundred heads who breathed out flames; son of Typhoeus and father of Cerberus and the Chimera and the Sphinx
    loup-garou, lycanthrope, werewolf, wolfman
    a monster able to change appearance from human to wolf and back again
    type of:
    imaginary being, imaginary creature
    a creature of the imagination; a person that exists only in legends or myths or fiction
  2. noun
    someone or something that is abnormally large and powerful
    synonyms: behemoth, colossus, giant, goliath
    see moresee less
    type of:
    anomaly, unusual person
    a person who is unusual
  3. noun
    a person or animal that is markedly unusual or deformed
    synonyms: freak, lusus naturae, monstrosity
    see moresee less
    the largest or most massive thing of its kind
    type of:
    mutant, mutation, sport, variation
    (biology) an organism that has characteristics resulting from chromosomal alteration
  4. noun
    a cruel wicked and inhuman person
    synonyms: demon, devil, fiend, ogre
    see moresee less
    someone who acts as if possessed by a demon
    type of:
    disagreeable person, unpleasant person
    a person who is not pleasant or agreeable
  5. noun
    (medicine) a grossly malformed and usually nonviable fetus
    synonyms: teras
    see moresee less
    type of:
    fetus, foetus
    an unborn or unhatched vertebrate in the later stages of development showing the main recognizable features of the mature animal
Word Family

Test prep from the experts

Boost your test score with programs developed by’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week