intelligence; secret information
Refers to information gathered secretly, especially for military or national security purposes. Often used in compounds like 諜報活動 (intelligence activities) or 諜報機関 (intelligence agency).
That country is strengthening its intelligence activities.
The intelligence agency obtained important information.
That country was carrying out intelligence activities against other nations.
She has been engaged in intelligence work for many years.
He works at a government intelligence agency.
スパイ refers to the person who spies, whereas 諜報 refers to the secret information or activity of gathering it, not the agent themselves.
Compound of 諜 (spy, secret investigation) and 報 (report, information). The exact historical derivation is uncertain, but the kanji combination conveys the meaning of 'secretly reported information'.