Slump
WordNet
noun
(1) A noticeable deterioration in performance or quality
"The team went into a slump"
"A gradual slack in output"
"A drop-off in attendance"
"A falloff in quality"
(2) A long-term economic state characterized by unemployment and low prices and low levels of trade and investment
verb
(3) Fall heavily or suddenly; decline markedly
"The real estate market fell off"
(4) Go down in value
"The stock market corrected"
"Prices slumped"
(5) Fall or sink heavily
"He slumped onto the couch"
"My spirits sank"
(6) Assume a drooping posture or carriage