flapping

1. not comparablethat flaps or flap

   flapping sails

plural flappings

1. countableuncountableAn instance where one, or something, flaps.

   The farmyard was dark and he tiptoed across it so that the turkeys wouldn't set up their gobbling and flapping.

   1970, Richard Carpenter, Catweazle, Harmondsworth: Puffin Books, page 24

2. countableuncountablehuman sciencesA phonological process found in many dialects of English, especially American English and Canadian English, by which intervocalic /t/ and /d/ surface as the alveolar flap [ɾ] before an unstressed syllable, so that words such as "metal" and "medal" are pronounced similarly or identically.
3. countableuncountablecommunicationsThe situation where a resource, a network destination, etc., is advertised as being available and then unavailable (or available by different routes) in rapid succession.
4. uncountableThe unlicensed racing of horses or greyhounds.

   Flapping is racing which is not licensed by the Jockey Club. […] Anyone found participating in, or even attending, flapping races is liable to be warned off.

   2016, Gerald Hammond, The Language of Horse Racing, page 81

   2 more examples

   Greyhound racing had its origins in whippet racing, which was derived in turn from hare coursing. By the early twentieth century, however, a form of dog racing held in 'flapping tracks' was a common pastime in the wastelands near working-class areas of industrial cities.

   2009, Mark Clapson, The Routledge Companion to Britain in the Twentieth Century, page 332

   Flapping is the arse end of greyhound racing, the lowest of the low. Part sport, part fairground attraction, flapping is the bare-knuckle fighting of dog racing.

   2016, David Matthews, Man Buys Dog

1. gerundparticiplepresentpresent participle and gerund of flap