How to say "betrayal" in Japanese

• 裏切りうらぎりCommon
  nounThe general word for betrayal: turning against a person, group, or cause that trusted you. When you are not sure which word fits, this is the natural choice.
  あの男おとこは裏切うらぎりもしかねない。↗

  He is capable of treachery.
• 背信はいしんCommon
  suru verb, no-adjectiveBetrayal understood as a breach of trust or faith; the word foregrounds the broken trust itself rather than the deed. Its senses also include infidelity.
  この報告ほうこくは彼かれの背信はいしんを裏付うらづけしている。↗

  This report confirms his betrayal.
• 変節へんせつCommon
  noun, suru verb, intransitive verbBetrayal as defection or apostasy: abandoning or reversing one's principles, creed, or allegiance. It is not the word for betraying someone's trust — it describes a turnabout in position.
• 寝返りねがえりCommon
  noun, suru verb, intransitive verbBetrayal as switching sides: someone who had been on your side turns and goes over to the other — a double-cross. For betrayal of trust in general, 裏切り is the word.
  こいつ、さっきまで俺おれの相棒あいぼうだったのに、もう寝返ねがえりやがった。↗

  This rat, up until just now he was my partner and now he's gone and turned on me.

Use 「裏切り」 for betrayal in general; 背信 for a breach of trust or faith (also infidelity); 変節 for abandoning one's principles or switching allegiance; 「寝返り」 for a double-cross, going over to the other side.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 裏切りうらぎりtreachery
• 背信はいしんbetrayal
• 変節へんせつbetrayal
• 内通ないつうsecret communication (with the enemy)
• 内応ないおうsecret understanding
• 寝返りねがえりbetrayal