"monster"
Word Nerd
Act 3,
Scene 2
Lines 355-378
Oberon
The word monster derives from the Latin verb monēre, to warn. The noun, monstrum, was an omen, a warning about the future. Over time, monstrum came to refer to anything extraordinary, particularly something horrible or atrocious. However when the word came into English, it had a very specific meaning: any mythological character which was half-man and half-animal, and that's how Oberon is using it here when referring to the ass-headed Bottom.