not a real father or a nature father (as distinct from foster father)
?【巳集中】【父部】 康熙筆畫:10畫,部外筆畫:6畫
《五音集韻》徒紅切,音同。父也。《正字通》從父從同。謂親之如父,與淮南假母義同。非生母故謂之假,非生父故謂之同。