erratic

3 definitions • 5 examples

moving or behaving in a way that is not regular, certain, or expected:

He drove in an erratic course down the road.

She can be very erratic; one day she is friendly and the next she'll hardly speak to you.

changing suddenly and unexpectedly:

an erratic schedule

something that is erratic is not regular, certain, or organized in its movement or behaviour:

The erratic behaviour of the stock market is making investors nervous.

Stocks closed up slightly after an erratic day of trading.