ニンベン師し

noun

forger

Obsolete slang for a forger, likely from underworld or criminal jargon. The term is not used in modern Japanese.

• 「ニンベン師し」は昔むかしの偽ぎ造ぞう者しゃを指さす隠いん語ごだったらしい。

  It seems that 'ニンベン師' was old slang for a forger.