intransitive verb
Definition: To fall or drop suddenly and steeply, often into something or from a height.
Example: The stock market plunged after the bad news was announced.
noun
Definition: The act of suddenly falling or diving into something, often water, or a quick swim or dip.
Example: She took a plunge into the cool water on a hot day.
transitive verb
Definition: To throw or push something suddenly and forcefully into a place or situation.
Example: She decided to plunge the vegetables into the boiling water.