slack vs slough

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. 

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. 

adv
  • Slackly. 

slough

noun
  • A muddy or marshy area. 

  • A small pond, often alkaline, many but not all formed by glacial potholes. 

  • Dead skin on a sore or ulcer. 

  • A type of swamp or shallow lake system, typically formed as or by the backwater of a larger waterway, similar to a bayou with trees. 

  • A state of depression. 

  • The skin shed by a snake or other reptile. 

  • A secondary channel of a river delta, usually flushed by the tide. 

verb
  • To shed (skin). 

  • To slide off (like a layer of skin). 

  • To discard. 

  • To commit truancy, be absent from school without permission. 

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