n.
- a large, ugly, and frightening imaginary creature.
▸an inhumanly cruel or wicked person.
▸humorous a rude or badly behaved child.
- a congenitally malformed or mutant animal or plant.
-
[as modifier]
informal extraordinarily large.
v.
Brit. informal criticize severely.
Etymology
ME: from OFr. monstre, from L. monstrum ‘portent or monster’, from monere ‘warn’.