1 (written 书面语) to become gradually weaker or less important 衰微；没落: My enthusiasm was waning rapidly.我的热情迅速减退。
2 (used about the moon) to appear slightly smaller each day after being full and round （指月亮）缺，亏 [OPP] wax ² 反义词为wax^2
wane²
/weɪn ||; wen/nounon the wane(written 书面语) becoming smaller, less important or less common 逐渐减弱；衰败；没落: The singer's popularity seems to be on the wane these days.这歌星的声望近来似乎不断降低。