Definitions
1.nounA terrifying and dangerous creature.
2.nounA bizarre or whimsical creature."The children decided Grover was a cuddly monster."
3.nounA cruel or antisocial person, especially a criminal."Get away from those children, you meatheaded monster!"
4.nounA horribly deformed person.
5.nounA badly behaved child, a brat."Sit still, you little monster!"
6.nounSomething unusually large."Have you seen those powerlifters on TV? They're monsters."
7.nounA prodigy; someone very talented in a specific domain."That dude playing guitar is a monster."
8.nounA non-player character that player(s) fight against in role-playing games.
9.verbTo make into a monster; to categorise as a monster; to demonise.
10.verbTo behave as a monster to; to terrorise.
11.verbTo harass.