Archaic term for a descendant or successor, especially in a lineage or family line. Not used in modern Japanese; replaced by words like 子孫 or 後継者.
In old documents, the word 胤裔 is used to refer to those who carry on a bloodline.
The exact derivation is uncertain; the kanji 胤 (bloodline, descendant) and 裔 (descendant, border) combine to form an archaic compound meaning 'descendant' or 'successor'.