scour vs slack

scour

noun
  • The removal of sediment caused by swiftly moving water. 

  • A place where wool is washed to remove grease and impurities prior to processing. 

  • A place scoured out by running water, as in the bed of a stream below a waterfall. 

verb
  • To (cause livestock to) suffer from diarrhoea or dysentery. 

  • To search an area thoroughly. 

  • To run with speed; to scurry. 

  • To clear the digestive tract (of an animal) by administering medication that induces defecation or vomiting; to purge. 

  • To move swiftly over; to brush along. 

  • To clean, polish, or wash (something) by rubbing and scrubbing it vigorously, frequently with an abrasive or cleaning agent. 

  • To remove debris and dirt (from something) by purging; to sweep along or off by a current of water. 

slack

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

  • 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. 

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

  • Small coal; coal dust. 

  • A valley, or small, shallow dell. 

adv
  • Slackly. 

verb
  • To slacken. 

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

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. 

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