slack vs staunch

slack

noun
  • Small coal; coal dust. 

  • 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. 

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

  • 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. 

verb
  • To slacken. 

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

adv
  • Slackly. 

staunch

noun
  • Synonym of afterdamp (“suffocating gases present in a coal mine after an explosion caused by firedamp”) 

adj
  • Strongly built; also, in good or strong condition. 

  • Not permitting water or some other liquid to escape or penetrate; watertight. 

  • Staying true to one's aims or principles; firm, resolute, unswerving. 

  • Dependable, loyal, reliable, trustworthy. 

  • Impermeable to air or other gases; airtight. 

  • Of a hunting dog: that can be depended on to pick up the scent of, or to mark, game. 

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