in the dark; in darkness
Often used in the set phrase 暗中模索 (あんちゅうもさく, 'groping in the dark') to describe a situation where one is acting without clear guidance or information. As a standalone noun, it is somewhat literary.
暗中模索の状態が続いている。
We are still groping in the dark.
彼は暗中で手探り
He groped his way forward in the dark.
groping in the dark; trial and error without clues
behind-the-scenes maneuvering; secret maneuvers
Compound of 暗 (あん, 'dark') and 中 (ちゅう, 'in, inside'). The exact historical derivation is uncertain, but the word is conventionally associated with the meaning 'in the dark'.