1An adult male native or inhabitant of East Asia, originally and chiefly in Japan; specifically a father or other man in a position of authority (sometimes as a form of respectful address). Also in extended use: any East Asian old man, especially in Korea or Vietnam (originally U.S. Military, slang).
2Specifically. A pimp; the male counterpart or companion of a mama-san.
3In full "papasan chair". A rattan chair consisting of a cushion in a large, bowl-shaped basket set on a cylindrical base.
Early 20th century; earliest use found in Lafcadio Hearn (1850–1904), author and translator. From Japanese papa-san from papa father (from English papa) + -san.