皇こう祖そ妣ひ

noun

deceased grandmother of the emperor

Highly formal, historical term referring specifically to the late grandmother of a reigning emperor. Used in official records or ceremonial contexts.

• 皇こう祖そ妣ひの御み霊たまに奉ほう告こくの儀ぎが執とり行おこなわれた。

  A ceremony was held to report to the spirit of the deceased imperial grandmother.