erratic

/ɪˈrætɪk/
adjective
  1. Not regular, predictable, or consistent; tending to change suddenly and without reason.
    • The stock market has been erratic this week, with prices jumping up and down.
    • Her erratic behavior worried her friends, as she would go from happy to angry in seconds.
    • The bus service has been erratic lately, sometimes arriving twenty minutes late.
  2. Moving or behaving in an irregular or unpredictable way, without a fixed course.
    • A small boat drifted in erratic circles after its engine failed.
    • The puppy ran in erratic patterns across the yard, chasing every butterfly it saw.
    • The erratic path of the tornado made it hard for forecasters to warn everyone in time.
noun
  1. A rock or boulder that has been carried from its original location by a glacier and left in a different area.
    • The large granite erratic in the middle of the field was left there by an ancient glacier.
    • Geologists studied the erratic to learn about the direction of ice flow thousands of years ago.
    • Hikers often stop to admire the massive erratic perched on the hillside.
What does "erratic" mean? | whatsthatwordmean | whatsthatwordmean