klatsch n.

c. 1300, "to strike with a quick, sharp motion, to slap," from Old English clæppan "to throb, beat," or from or influenced by its Old Norse cognate, klappa, a common Germanic echoic verb (compare Old Frisian klapa "to beat," Old High German klaphon, German klappen, Old Saxon klapunga).

Meaning "to make a sharp noise" is late 14c. Of hands, "to beat together to get attention or express joy," from late 14c. Without specific mention of hands, "to applaud, to manifest approbation by striking the hands together," 1610s. To clap (someone) on the back is from 1520s and retains the older sense. Related: Clapped; clapping.

"gossip over cups of coffee," 1877, from German Kaffeeklatsch, from kaffee "coffee" (see coffee) + klatsch "gossip" (see klatsch).

THE living-room in a German household always contains a large sofa at one side of the room, which is the seat of honor accorded a guest. At a Kaffeeklatsch (literally, coffee gossip) the guests of honor are seated on this sofa, and the large round table is wheeled up before them. The other guests seat themselves in chairs about the table. [Mary Alden Hopkins, "A 'Kaffeeklatsch,'" "Boston Cooking-School Magazine of Culinary Science and Domestic Economics," May 1905]