How to say "tip-off" in Japanese

• 密告みっこくCommon
  noun, suru verb, transitive verbThe common word for secretly informing against someone, with a strong nuance of betrayal. As a tip-off, it is secret information passed on to the authorities about another person's wrongdoing.
  スリの一人ひとりは残のこりの二人ふたりを密告みっこくした。↗

  One of the pickpockets blew the whistle on the other two.
• たれこみ
  nounA less common word, usually written in kana, for a tip-off to the authorities; the nuance is of leaking information, often anonymously. A typical case is an anonymous tip to the police.
• 内報ないほう
  noun, suru verb, transitive verbA less common word for a tip-off in the sense of secret information passed on confidentially; it centers on the information itself rather than denunciation. Think of private advance notice of a decision.
• ちんころ
  noun, suru verbLess common slang for a tip-off to the authorities or telling on someone, with much the same coverage as たれこみ; it is seldom the word you want outside casual talk.

Use 密告, the common word, for secretly informing against someone; 「たれこみ」 for an anonymous tip-off to the authorities; 内報 for confidential advance information; 「ちんころ」 only as slang for telling on someone.

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

• 密告みっこくanonymous report
• たれこみtip-off (to the authorities)
• 内報ないほうtip-off
• ちんころtip-off (to the authorities)