Translation guide
The English verb "betray" covers a range of meanings from personal disloyalty to revealing secrets or showing unintended emotions. This guide organizes the most common and useful Japanese expressions by these distinct meanings, helping learners choose the right word for the context.
To be disloyal or unfaithful to someone who trusts you, such as a friend, partner, or organization.
The most common and direct translation for personal betrayal. It can be used for friends, lovers, allies, or one's own principles.
He betrayed his best friend.
She betrayed my trust.
Literally 'to flip sides while sleeping', meaning to switch allegiance, often in a dramatic or opportunistic way. Common in historical or political contexts.
The general betrayed his side and went over to the enemy.
To go against or defy someone's expectations, orders, or trust. Often used for betraying a promise or principle.
He betrayed his promise.
To disclose secret information, often to an enemy or unauthorized person.
A straightforward phrase meaning 'to leak a secret'. It implies a breach of confidence.
He betrayed company secrets.
To inform on someone, often to authorities. Carries a nuance of betrayal through reporting.
Can also be used for betraying by revealing secrets, especially in dramatic contexts.
To show one's true feelings or thoughts without meaning to, often through facial expression or action.
Literally 'one's true feelings come out'. Used when someone accidentally reveals what they really think.
His expression betrayed his true feelings.
To show on one's face. Often used when emotions are visible despite efforts to hide them.
My surprise betrayed itself on my face.
When one's voice trembles, betraying nervousness or emotion. More specific physical betrayal.
To cheat on a partner or be sexually unfaithful.
When describing how a facial expression or action unintentionally reveals feelings, using 裏切る directly can sound unnatural. Instead, use phrases like 本音が出る or 顔に出る.
裏切る is the general term for betrayal of trust. 背く emphasizes going against rules, expectations, or orders, and is often used for abstract things like promises or principles.
He betrayed his comrades to the police.
スパイが国を裏切って情報を渡した。
The spy betrayed his country and handed over information.
His voice trembled, betraying his nervousness.
He betrayed his wife by having an affair.