Capricious means changing suddenly and unpredictably, often without any good reason. Someone capricious might be your friend one day and ignore you the next, then act like nothing happened the day after that. A capricious person makes decisions based on whims and moods rather than logic or consistency.

Weather can be capricious too: a sunny morning might suddenly turn stormy, then clear up again by afternoon. A capricious wind shifts direction without warning, making it hard for sailors to navigate. March weather is famously capricious, swinging between winter cold and spring warmth.

The word suggests extreme unpredictability. A capricious teacher might cancel a test on a whim, then surprise everyone with a pop quiz the next day, with no pattern anyone can predict. Simple inconsistency means sometimes doing one thing and sometimes another, but capriciousness involves wild swings that follow no logic.

Capricious behavior makes life difficult for others because they never know what to expect. You can't plan around capriciousness or rely on it. When someone calls a rule or decision capricious, they mean it seems arbitrary and unfair, like it was made on a whim rather than for a real reason. The unpredictability is what makes something truly capricious.