Translation guide
A person who switches allegiance from one side to another, especially in politics or conflict. In Japanese, this is expressed through nouns describing betrayal or changing sides, and related verbs.
The learner wants to refer to someone who has switched sides, often with a negative connotation.
The most common and direct translation. Literally 'betrayer', it carries a strong negative connotation and is used for anyone who betrays trust or switches allegiance.
He is a turncoat.
I won't forgive a turncoat.
Specifically refers to someone who switches sides, often in a conflict or competition. '寝返る' means to change sides or betray. Slightly less common than 裏切り者 but very precise.
A turncoat appeared in the middle of the battle.
A literary or formal term for someone who changes their principles or allegiance. '変節' means change of principle, and '漢' is a somewhat old-fashioned suffix for man. Rare in everyday speech.
He went down in history as a turncoat.
The learner wants to describe the action of becoming a turncoat, rather than the person.
The most common verb for switching sides or betraying one's group. Can be used in political, military, or even business contexts.
He turned coat and went over to the enemy.
General verb for betrayal. While broader than 'turncoat', it is often used when someone betrays their group's trust by switching allegiance.
Literally 'to change saddles', this idiomatic phrase means to switch sides or change one's affiliation, often for opportunistic reasons. Commonly used in politics or business.
裏切り者 is the general term for a betrayer and can be used in any context of broken trust. 寝返り者 specifically implies switching to the opposing side, often in a conflict or competition. Use 寝返り者 when the act of changing allegiance is central.
He is a turncoat. I trusted him.
Because of that turncoat, the plan was leaked.
Do not attempt to translate 'turncoat' literally as 'コートを裏返す' or similar. The English idiom does not carry over. Use the provided Japanese terms for betrayal or changing sides.
Just before the election, the lawmaker turned coat and joined the opposition party.
He turned coat and leaked the secrets.
He turned coat in search of better terms.