n. 25B6; verb
he slumped into a chair : SIT HEAVILY, flop, flump, collapse, sink, fall; informal plonk oneself.
houses prices slumped : FALL STEEPLY, plummet, tumble, drop, go down; informal crash, nosedive.
reading standards have slumped : DECLINE, deteriorate, degenerate, worsen, slip, go downhill.
25B6; noun
a slump in profits : STEEP FALL, drop, tumble, downturn, downswing, slide, decline, decrease; informal nosedive.
an economic slump : RECESSION, economic decline, depression, slowdown, stagnation.
rise, boom.