noun

1. any plant or animal of abnormal shape or structure, as one greatly malformed or lacking some parts; monstrosity
2. any imaginary creature part human and part animal in form, as a centaur, or made up of the parts of two or more different animals, as a dragon
3. something monstrous
4. a person so cruel, wicked, depraved, etc. as to horrify others
5. any huge animal or thing
6. Pathology a malformed fetus, esp. one with an excess or deficiency of limbs or parts; teratism

Etymology: ME monstre < OFr < L monstrum, divine portent of misfortune, monster < monere, to admonish, warn: see monitor

adjective