noun
act of disobedience; betrayal; breach; violation
Refers to an act that goes against rules, expectations, or loyalty; often used in formal or legal contexts.
契約に違反する背反行為は許されない。
An act of breach that violates the contract is not tolerated.
彼の背反行為は会社への信頼を裏切るものだった。
His act of betrayal was a breach of trust toward the company.
Compound of 背反 (betrayal, violation) and 行為 (act, deed). The exact historical derivation of 背反 is uncertain, but it is conventionally associated with the meaning of going against or turning one's back on something.