unfair treatment of somebody who trusts you synonym treachery背叛;背信弃义 In Act 2 he learns of Giovanni’s perfidy and swears revenge. 在第二幕中,他知道了乔瓦尼的背信弃义,发誓要报仇。
Word Originlate 16th cent.: via French from Latin perfidia, from perfidus ‘treacherous’, based on per- ‘to ill effect’ + fides ‘faith’.