wax and wane
盈亏变化，波动不定
书面或口语·描述波动或循环
英文释义
to go through cycles of increase and decrease, rise and fall; to fluctuate in intensity or popularity
例句
The popularity of that singer has waxed and waned over the years.
典故来源
源自月亮的盈亏现象，比喻事物周期性的增减或变化。