plummet
Synonym discussion
Sense: verb/1
For this sense, plummet is one of the strongest common verbs for a very fast downward movement or decline. It often appears with prices, sales, temperatures, and support in news writing. Plunge is close, but it can also suggest a deliberate jump or a sudden move into water or darkness. Tumble often adds a feeling of losing control or turning as something falls. Nosedive is vivid and slightly informal, especially for planes or sudden business declines. Drop is the broad neutral choice and sounds much less dramatic. So a reporter might write, 'Shares plummeted after the warning,' while a parent might say, 'The toy tumbled down the stairs.'
Etymology
Plummet first named the weight used on a plumb line by builders. That noun came into English through Old French from a Latin word for lead, because the tool was often made of lead. Later, English extended the noun into a verb: if something moved down like that hanging weight, it could be said to plummet.