flapping vs slack

flapping

noun
  • An instance where one flaps. 

  • The situation where a resource, a network destination, etc., is advertised as being available and then unavailable (or available by different routes) in rapid succession. 

  • The unlicensed racing of horses or greyhounds. 

  • A 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. 

adj
  • that flaps or flap 

slack

noun
  • The part of anything that hangs loose, having no strain upon it. 

  • Unconditional listening attention given by client to patient. 

  • A temporary speed restriction where track maintenance or engineering work is being carried out at a particular place. 

  • A tidal marsh or shallow that periodically fills and drains. 

  • Small coal; coal dust. 

  • A valley, or small, shallow dell. 

adj
  • Moderately warm. 

  • Vulgar; sexually explicit, especially in dancehall music. 

  • Not active or busy, successful, or violent. 

  • Excess; surplus to requirements. 

  • Lax; not tense; not firmly extended. 

  • Lacking diligence or care; not earnest or eager. 

  • Lax. 

  • Moderate in speed. 

  • Weak; not holding fast. 

adv
  • Slackly. 

verb
  • To slacken. 

  • To lose cohesion or solidity by a chemical combination with water; to slake. 

How often have the words flapping and slack occurred in a corpus of books? (source: Google Ngram Viewer )