A terrifying and dangerous creature. / A bizarre or whimsical creature. / A cruel, heartless, or antisocial person, especially a criminal. / (medicine, archaic) A severely deformed person.

(informal) Very large; worthy of a monster. / (informal) Great; very good; excellent.

To make into a monster; to categorise as a monster; to demonise. / To behave as a monster to; to terrorise. / (chiefly Australia) To harass.

a venomous lizard, Heloderma suspectum, that lives in the deserts of the southwestern USA and northwestern Mexico

A blue creature from the children's television show Sesame Street who is intensely fond of cookies.

Frankenstein's monster, the creature from Mary Shelley's 1818 novel

A thing that is cobbled together from parts of other things. / A creation that overpowers or slips out of the control of its creator, often proceeding to turn on its creator or harm others.

Hideous or frightful. / Enormously large. / Freakish or grotesque. / Of, or relating to a mythical monster; full of monsters. / (obsolete) Marvellous; exceedingly strange; fantastical.

An organism showing abnormal development or deformity. / A monstrous person, thing, or act. / The state of being monstrous.

(Christianity) An ornamental, often precious receptacle, either open or with a transparent cover, in which the sacramental bread (consecrated host) is placed for Eucharistic adoration.