waning ['weɪnɪŋ]

以下由轻松背单词网站提供

附加级

adj.（月亮）渐亏的，逐渐减弱或变小的n.月亏v.衰落( wane的现在分词 )；（月）亏；变小；变暗淡

Her enthusiasm for the whole idea was waning rapidly. 她对整个想法的热情迅速冷淡了下来。
The day is waning and the road is ending. 日暮途穷。来自《现代汉英综合大词典》