noun
covert action; covert operations
Refers to secret or undercover activities, often in military, intelligence, or espionage contexts.
その組織は隠密行動に長けている。
The organization excels at covert operations.
隠密行動の詳細は明かされなかった。
The details of the covert action were not disclosed.
Compound of 隠密 (secret, stealth) and 行動 (action, behavior). The exact historical derivation is uncertain, but the term is used in modern Japanese for covert operations.