An example of eavesdrop is to listen to your neighbors' argument through a vent in your apartment.
Other Word Forms
Origin of eavesdrop
- Probably back-formation from eavesdropper one who eavesdrops from Middle English evesdropper from evesdrop place where water falls from the eaves from Old English yfesdrype upo in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition