What is the meaning of slump?

noun

• A noticeable deterioration in performance or quality.
  • usage: "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
  • synonyms: slack, drop-off, falloff, falling off
• A long-term economic state characterized by unemployment and low prices and low levels of trade and investment.
  • synonyms: depression, economic crisis

verb

• Assume a drooping posture or carriage.
  • synonyms: slouch
• Fall or sink heavily.
  • usage: "He slumped onto the couch"; "My spirits sank"
  • synonyms: slide down, sink
• Fall heavily or suddenly; decline markedly.
  • usage: "The real estate market fell off"
  • synonyms: fall off, sink
• Go down in value.
  • usage: "the stock market corrected"; "prices slumped"
  • synonyms: decline, correct