slump
noun
a noticeable deterioration in performance or quality
“the team went into a slump”
“a gradual slack in output”
a long-term economic state characterized by unemployment and low prices and low levels of trade and investment
verb
assume a drooping posture or carriage
Synonymsslouchfall or sink heavily
“He slumped onto the couch”
“My spirits sank”
fall heavily or suddenly; decline markedly
“The real estate market fell off”
go down in value
“the stock market corrected”
“prices slumped”
Source: WordNet 3.1, Princeton University