slump2 [countable, usually singular]
a sudden decrease in prices, sales, profits etc
a slump in car sales
a period when there is a reduction in business and many people lose their jobs [≠ boom]:
The war was followed by an economic slump.
a worldwide slump
3 especially American EnglishDS
a period when a player or team does not play well
in a slump
The Dodgers have been in a slump for the last three weeks.