Synonyms: betray, be unfaithful to, do the dirty on, mess around, two-time
Betray
1. 背叛;出卖;对...不忠[(+to)]
That man is capable of betraying his friends.
那家伙会出卖朋友。
2. 泄漏,透露
He would suffer death rather than betray the secret.
他宁死也不肯泄露机密。
3. (无意中)暴露,显示[(+to)][+wh-]
Her red face betrayed her nervousness.
她涨红的脸显示她很紧张。
Unfaithful
1. 不忠实的;不忠于职守的[(+to)]
He is unfaithful to his duty.
他不忠于职守。
2. (对配偶)不忠实的;有外遇的[(+to)]
Her husband is unfaithful to her.
她的丈夫对她不忠实。
3. (翻译、版本等)不准确的,不可靠的