1. to jump or dive quickly and forcefully into water
2. to move or fall suddenly downward or forward
3. to decrease suddenly and dramatically

1. a sudden jump or dive, especially into water
2. a sudden fall or drop

Examples

• She decided to plunge into the cold lake.
• The car plunged off the cliff into the valley below.
• Stock prices plunged after the announcement.
• He plunged the knife into the watermelon.
• The swimmer took a graceful plunge from the diving board.
• The company’s profits took a sudden plunge.
• The roller coaster made a steep plunge down the track.
• She plunged her hands into the soapy water.