eavesdrop

I don't know if I'm one of the few people who's too stupid to have already known the etymology of this word, so I apologize if this is common knowledge, because it's new to me.

The OED defines the verb "eavesdrop" as:
"To stand within the ‘eavesdrop’ of a house in order to listen to secrets; hence, to listen secretly to private conversation. Also trans. To listen secretly to (conversation); formerly also, to listen within the ‘eavesdrop’ of (a house); to listen to the secrets of (a person)."

That definition didn't even satisfy my ignorace's hunger. I had to look up "eaves" which the OED defines as:
"The edge of the roof of a building, or of the thatch of a stack, which overhangs the side."

"Eaves" is an Old English word as is "drop."