n. & v.
--n.
1. a sudden severe or prolonged fall in prices or values of commodities or securities.
2 a sharp or sudden decline in trade or business usu. bringing widespread unemployment.
3 a lessening of interest or commitment in a subject or undertaking.
--v.intr.
1. undergo a slump; fail; fall in price.
2 sit or fall heavily or limply (slumped into a chair).
3 lean or subside.
Etymology: 17th c., orig. 'sink in a bog': imit.