expression, i-adjective
helpless; at a loss; having no choice
Describes a situation where one has no means or options left; often implies frustration or desperation.
問題が複雑すぎて、なす術もなかった。
The problem was too complicated, and I was at a loss for what to do.
突然の停電で、なす術もなく暗闇に包まれた。
With the sudden blackout, we were helplessly enveloped in darkness.
From 為す (nasu, 'to do') + 術 (sube, 'way, means') + も (mo, 'even') + ない (nai, 'not'). Literally 'there is not even a way to do (something)'.