noun. Deliberate breach of faith; calculated violation of trust; treachery.

noun. The act or an instance of treachery.

noun. Breach of faith or trust; base treachery; faithlessness.

noun. Synonyms See perfidious.

noun. The act of violating faith or allegiance; violation of a promise or vow, or of trust reposed; faithlessness; treachery.

noun. A state or act of violating faith or allegiance; violation of a promise or vow, or of trust reposed; faithlessness; treachery.

noun. Specifically, in warfare, an illegitimate act of deception, such as using symbols like the Red Cross or white flag to gain proximity to an enemy for purposes of attack.

noun. A state or act of deceit.

noun. an act of deliberate betrayal

noun. betrayal of a trust

"But much as she loved England she was very loud in denouncing what she called the perfidy of the mother to the brightest of her children."

perfidious  perfidiously  

avarice  barbarity  betrayal  deceit  depravity  

betrayal  deceit  dirty pool  dirty trick  dirty work