mama-san UK /ˈmaməˌsan/US /ˈmɑməˌsɑn/ noun2 •A mother, in Japan or East Asia. •A woman in a position of authority, especially the madam of a geisha bar.‘I had a last go at the film festival, hoping those Thai mammasans would stir you up with some juice kiddy-porn.’ — 2000 formsmama-sans