<p><strong>Noun</strong></p><ul><li>a person who heedlessly or maliciously reveals private or confidential matters.</li><li>tattler.</li><li>talebearer.</li><li>a thing serving to reveal or disclose something.</li><li>any of various indicating or registering devices, as a time clock.</li><li>Music: a gauge on an organ for indicating the air pressure.</li><li>an indicator showing the position of a ship's rudder.</li><li>a row of strips hung over a track to warn train crew members on freight trains that a low bridge, tunnel, or the like is approaching.</li><li>Yachting: (on a sailboat) a feather, string, or similar device, often attached to the port and starboard shrouds and to the backstay, to indicate the relative direction of the wind.</li><li>Squash: a narrow piece of metal across the front wall of a court, parallel to and extending 17 inches (43.2 centimeters) above the base: a ball striking this is an out.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) to utter by clacking.</li><li>to cause to clack: He clacked the cup against the saucer.</li></ul><p><strong>Noun</strong></p><ul><li>a clacking sound.</li><li>something that clacks, as a rattle.</li><li>rapid, continual talk; chatter.</li></ul>