Caught Eavesdropping
Meaning
A person found to be deliberately trying to overhear a conversation not intended for his/her ears.
Origin
The phrase goes back centuries to the time when most houses had no gutters – the rain dripped off the roofs but the roofs themselves projected well beyond the walls. This area inside where the water dripped was known originally as the Eavesdrop, and later as the Eavesdrop. People sheltering here were somewhat protected from the rain, but could also overhear what was going on in the house.