英语词源字典 - 在线词源网站

eaves [eaves 词源字典]: eaves: [OE] The etymological meaning of eaves appears to be ‘going over the edge, projecting’. It comes from a prehistoric Germanic *obaswa, which was probably formed on *ob-, the base from which English over ultimately derives. The eavesdrip or eavesdrop is, or was, the area of ground on which rainwater thrown off by the eaves falls, so that somebody who stood within this area, with his or her ear to the door or window trying to listen in on private conversations, became known as an eavesdropper [15].
=> over[eaves etymology, eaves origin, 英语词源]
tap (v.2): "to supply with a tap," late Old English tæppian, from source of tap (n.1); compare German zapfen "to tap." Meaning "to draw liquor with a tap" is from mid-15c. Extended sense "make use of" is first recorded 1570s. Meaning "listen in secretly" (1869), originally was with reference to telegraph wires. Tapped out "broke" is 1940s slang, perhaps from the notion of having tapped all one's acquaintances for loans already (compare British slang on the tap "begging, making requests for loans," 1932).
tap (n.3): "device to listen in secretly on telephone calls," 1923, from tap (v.2) in the "listen secretly" sense.