erratic
The stock market's erratic behavior made investors nervous.
The stock market's unpredictable movements caused anxiety among investors.
unpredictable and likely to change suddenly or irregularly
Her erratic mood swings made it hard to plan anything with her.
Her unpredictable changes in mood made scheduling difficult.
The erratic weather patterns disrupted the outdoor wedding.
The unpredictable weather changes ruined the outdoor ceremony.
Often describes behavior, weather, or systems that lack consistency.
Collocations
Pro Tip
Avoid overusing 'erratic'
While 'erratic' is precise, it can sound overly formal. Consider 'unpredictable' or 'inconsistent' in casual contexts.
Gold Rule
Erratic vs. eccentric
'Erratic' implies unpredictability or inconsistency, while 'eccentric' describes unconventional but deliberate behavior. An erratic person may act unpredictably; an eccentric person may act unusually by choice.
Word Origin
From Latin *erraticus*, meaning 'wandering' or 'roaming,' derived from *errare* ('to wander, stray'). The word entered English in the 17th century, initially describing physical wandering (e.g., erratic rocks left by glaciers) before extending to abstract unpredictability.
Usage Notes
Used to describe both concrete (e.g., movements) and abstract (e.g., decisions) phenomena that deviate from expected patterns. Avoid using for minor variations; reserve for significant unpredictability.