Webster's Revised Unabridged Dictionary · 1913

Eavesdrop

Eavesdrop (ēvz"drop`) , intransitive verb

[Eaves + drop.]

To stand under the eaves, near a window or at the door, of a house, to listen and learn what is said within doors; hence, to listen secretly to what is said in private.
To eavesdrop in disguises. — Milton

Eavesdrop , noun

The water which falls in drops from the eaves of a house.