Cách sử dụng
The word 'perfidious' means to be dishonest, deceitful or disloyal, especially to someone who trusted you. It can be used in situations where someone betrays the trust of another person, such as a friend or a business partner. For example, if a friend promises to keep a secret but later tells others, you could say they were being perfidious. It is a strong word with a negative connotation, so it should be used carefully and in appropriate contexts.