noun, noun which may take the genitive case particle 'no'
Often used adverbially as 暗々裏に to mean something is done in secret, behind the scenes, or without being openly acknowledged. Slightly literary or formal in tone.
彼らは暗々裏に計画を進めていた。
They were advancing the plan secretly.
その決定は暗々裏に行われた。
The decision was made covertly.
Compound of 暗々 (reduplication of 暗 'dark') and 裏 'back, behind', literally 'in the dark behind'. The exact historical derivation is uncertain, but the meaning is transparent from its components.