弧こ灯とうことうMeanings1nounarc lampTechnical term for a lamp that produces light via an electric arc. Not an everyday word; typically encountered in historical or technical contexts.19世せい紀きには、街がい灯とうとして弧こ灯とうが使つかわれていた。In the 19th century, arc lamps were used as streetlights.
