Something of unnatural size, shape, or quality; a prodigy; an enormity; a marvel.
- An imaginary or legendary creature, such as a centaur or Harpy, that combines parts from various animal or human forms.
- A creature having a strange or frightening appearance.
- An animal, a plant, or other organism having structural defects or deformities.
- Pathology A fetus or an infant that is grotesquely abnormal and usually not viable.
- A very large animal, plant, or object.
- One who inspires horror or disgust: a monster of selfishness.
- Informal Extremely large; monstrous: a monster hit at the box office; ate a monster steak.