curb vs slack

curb

verb
  • To crouch; to cringe. 

  • To rein in. 

  • To bend or curve. 

  • To furnish with a curb, as a well; to restrain by a curb, as a bank of earth. 

  • To damage vehicle wheels or tires by running into or over a pavement curb. 

  • To check, restrain or control. 

  • To bring to a stop beside a curb. 

noun
  • Something that checks or restrains; a restraint. 

  • A swelling on the back part of the hind leg of a horse, just behind the lowest part of the hock joint, generally causing lameness. 

  • A concrete margin along the edge of a road; a kerb (UK, Australia, New Zealand) 

  • A riding or driving bit for a horse that has rein action which amplifies the pressure in the mouth by leverage advantage placing pressure on the poll via the crown piece of the bridle and chin groove via a curb chain. 

  • A sidewalk, covered or partially enclosed, bordering the airport terminal road system with adjacent paved areas to permit vehicles to off-load or load passengers. 

  • A raised margin along the edge of something, such as a well or the eye of a dome, as a strengthening. 

slack

verb
  • To slacken. 

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

adv
  • Slackly. 

noun
  • 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. 

  • 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. 

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