fluctuation

n. /ˌflʌktʃuˈeɪʃn/ C2

波动；起伏

An irregular rising and falling change in number or amount.

仙境例句

The King's mood showed a strange fluctuation: happy one moment, angry the next.

国王的心情起伏不定：这会儿还高兴，下一刻就生气了。