noun
grandchild of Amaterasu; Ninigi no Mikoto
Archaic mythological term specifically referring to Ninigi no Mikoto, the grandson of the sun goddess Amaterasu, who descended to earth.
天孫降臨の神話では、天孫が葦原中国に降り立ったとされる。
In the myth of the descent of the heavenly grandchild, it is said that the grandchild of Amaterasu descended to the land of Ashihara.
noun
descendant of Amaterasu; imperial lineage; emperor
Extended use referring to any descendant of Amaterasu, especially the imperial family or the emperor himself. Often found in classical or poetic contexts.
天皇は天孫の末裔とされている。
The emperor is considered a descendant of the heavenly grandchild.
Refers to the entire myth of the descent of the heavenly grandchild, while 天孫 specifically denotes the grandchild himself.
Compound of 天 (heaven) and 孫 (grandchild), with the honorific prefix 御 (mi) in the longer form 皇御孫. The reading すめみま is archaic and associated with Shinto mythology.