1. in a way that cannot be predicted or expected; in an irregular or erratic manner

Examples

• The weather has been changing unpredictably this week.
• Stock prices moved unpredictably after the announcement.
• She reacted unpredictably to criticism, sometimes laughing and sometimes crying.
• The old car engine runs unpredictably on cold mornings.
• His mood swings unpredictably from happy to sad.
• The river’s water level rises unpredictably during storm season.