caprice
kəˈpriːs
noun
a sudden and unaccountable change of mood or behaviour.
the caprices of the electorate
whim,whimsy,vagary,fancy,notion,fad,freak,humour,impulse,quirk,eccentricity,foible,crotchet,urge,fickleness,changeableness,volatility,inconstancy,capriciousness,fitfulness,unpredictability