Definition of 'Slump'
A slang term denoting a period of poor performance or inactivity in an economy, market or industry. In economic terms, a slump specifically refers to a recession, signaling a slow down of business activity.
Investopedia explains 'Slump'
An industry may experience a slump when overall activity begins to decline. In the loan industry, a slump may represent a period of tight lending policies. Since it is more difficult to get a loan, overall lending volumes will drop.
Slumps apply to financial markets as well. When the stock market enters a slump, share prices and trading volume will usually be lower.