lightness: implies a lack of weight and seriousness and sometimes an instability or careless heedlessness: the only bit of ~ in a dreary, ponderous drama.


levity: suggests trifling or unseasonable gaiety: injected a moment of ~ in the solemn proceedings.   （trifle不严肃对待玩笑to do something without serious purpose，如trifled with someone's feelings玩弄某人感情）  （unseasonable有2个意思: 1、和季节不符的not in keeping with the season，如a sudden unseasonable blizzard突然的反常（反季节）暴风雪， 2、不合时宜的badly timed，如it was the unseasonable moment for a joke讲的笑话不合时宜）


frivolity: suggests irresponsible indulgence in gaieties or in idle speech or conduct: a playgirl living a life of uninterrupted ~.  （indulge沉溺，是指过度满足excessive satisfaction，如occasionally indulged myself with shopping我偶尔大肆购物）

flippancy: implies an unbecoming levity especially in speaking of grave or sacred matters: spoke of the bombing with annoying ~.  （unbecoming言行和身份品格不符，不得体implies behavior or language beneath or unsuitable to one's status or character，如conduct unbecoming an officer和军官身份不符的行为）


volatility: implies such lightness or fickleness of disposition as prevents long attention to any one thing: the ~ of the public interest in foreign aid.    （fickle多变不可靠changeable and unreliable, 如fickle weather/friend变化无常的天气，靠不住的朋友)


flightiness: implies extreme volatility that may approach loss of mental balance: the ~ of my grandmother in her old age.  这个词形容人感情不专一时语气很重，意思是水性杨花: 像流水那样易变，像杨花那样轻飘，比喻人的感情不专一


lightness轻松: 指不庄重严肃，有时表示不稳定，levity轻佻: 表示玩笑般不合时宜的欢快(gaiety完全无忧无虑)，frivolity轻闲无聊: 表示在欢快懒散中沉溺，不负责任，flippancy言语轻佻: 一般指谈论严肃事情时轻佻不得体，volatility易变不稳: 性格浮躁易变、注意力不集中，flightiness易变轻浮: 表示极端易变不稳定，几乎精神失常。


记忆方法: 1）首字母LLFFVF排列成1V2L3F想成123狼群<==最不轻浮的动物     （狼群有高度的组织性，目标和分工明确、执行力强。《狼图腾》说，其他动物被猎人夹子夹到后，只能等死，狼却会咬断自己的腿逃生，老狼会帮小狼咬掉小狼的腿，所以说狼群可能是最不轻浮的动物）


         2）轻浮的意思是在应该严肃的时候表现得欢快无所谓mean gaiety or indifference when seriousness is called for.