Definition from macmillandictionary.com
This was not the time to be plunging into some new business venture.
He plunged his arm into the sack once more.
Plunge the sliced onions into boiling water.
The city was plunged into total darkness when the entire electrical system failed.
The country is plunging into recession once more.
Four police officers plunged into freezing water to rescue a man yesterday.