/ ˈplʌmɪt; NAmE / verb
[ v ] to fall suddenly and quickly from a high level or position
SYN plunge :
Share prices plummeted to an all-time low.
Her spirits plummeted at the thought of meeting him again.
The jet plummeted into a row of houses.
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WORD ORIGIN
late Middle English (as a noun): from Old French plommet small sounding lead, diminutive of plomb lead. The current verb sense dates from the 1930s.