See nose dive in Webster's New World Roget's A-Z Thesaurus II
verb
To come to the ground suddenly and involuntarily:
drop, fall, go down, pitch, plunge, spill, topple, tumble. Idiom: take a fall (or header) (or plunge) (or spill) (or tumble). See riseTo undergo a sharp, rapid descent in value or price:
dive, drop, fall, plummet, plunge, sink, skid, slump, tumble. Idiom: take a sudden downtrend (or downturn). See increase
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