clack

From Middle English clacken, clakken, claken, from Old English *clacian (“to slap, clap, clack”); suggested by clacu (“din; harm, injury”)}}, from Proto-Germanic *klakōną (“to clap, chirp”), from Proto-Indo-European *glag- (“to make a noise, clap, twitter”), from Proto-Indo-European *gal- (“to roop, scream, shout”). Cognate with Scots clake, claik (“to utter cries", also "to bedaub, sully with a sticky substance”), Dutch klakken (“to clack, crack”), Low German klakken (“to slap on, daub”), Norwegian klakke (“to clack, strike, knock”), Icelandic klaka (“to twitter, chatter, wrangle, dispute”).

clack (plural clacks)

1. An abrupt, sharp sound, especially one made by two hard objects colliding repetitively; a sound midway between a click and a clunk.
2. Anything that causes a clacking noise, such as the clapper of a mill, or a clack valve.
3. Clatter; prattle.
   • South

     whose chief intent is to vaunt his spiritual clack

4. (colloquial) The tongue.

clack (third-person singular simple present clacks, present participle clacking, simple past and past participle clacked)

1. (intransitive) To make a sudden, sharp noise, or succession of noises; to click.
   • Thackeray

     We heard Mr. Hodson's whip clacking on the shoulders of the poor little wretches.

2. (transitive) To cause to make a sudden, sharp noise, or succession of noises; to click.
3. To chatter or babble; to utter rapidly without consideration.

   (Can we find and add a quotation of Feltham to this entry?)

   • 1953, Janice Holt Giles, The Kentuckians

     The women bunched up in little droves and let their tongues clack, and the men herded together and passed a jug around and, to tell the truth, let their tongues clack too.

4. (Britain) To cut the sheep's mark off (wool), to make the wool weigh less and thus yield less duty.