eaves [OE] In Old English eaves, then spelled efes, was a singular word, but the -s at the end made people think it was a plural, which is how we treat it today. If you eavesdrop you secretly listen to a conversation. The word was formed in the early 17th century from the old word eavesdropper [LME], ‘a person who listens from under the eaves’. Eavesdropper came from the noun eavesdrip or eavesdrop [OE], ‘the ground on to which water drips from the eaves’. This was a concept in an ancient law which banned building closer than two feet from the boundary of your land, in case you damaged your neighbour’s land by ‘eavesdrop’.