imperial ancestor; divine ancestor of the imperial line
Archaic Shinto term referring to the ancestral kami of the Japanese imperial family, especially Amaterasu. Used in classical Japanese and religious contexts.
Amatsu-mioya is enshrined as the ancestral deity of the imperial house.
皇祖 is a more general term for imperial ancestors, while 天津御祖 specifically refers to the divine ancestor in Shinto context.
天照大神 is the specific name of the sun goddess, whereas 天津御祖 is a title meaning 'divine ancestor'.
Compound of 天津 (amatsu, 'heavenly') + 御祖 (mioya, 'august ancestor'). The exact historical derivation is uncertain, but the term is deeply rooted in Shinto mythology.