unpredictable

Definitions

Not able to be foreseen or known beforehand.

Tending to change in ways that cannot be anticipated; erratic.

Examples

The weather in the mountains is notoriously unpredictable, so always pack a raincoat.

Her unpredictable mood swings made it difficult for the team to plan the project effectively.

The stock market has been highly unpredictable lately due to global economic shifts.

Synonyms

erratic capricious volatile fickle random uncertain changeable

Antonyms

predictable reliable consistent steady dependable certain stable