one's girlfriend, usu. older
I'd love to shoot some hoops tonite, but I'm going over to mama san's for a little horizontal relaxation.
Noun; A woman who cleans and presses your uniform in Okinawa. Regularly works directly out of the barracks.
Marine A: "Who got your uniform looking so sharp?"
Marine B: "I took it down to my mama san and she took care of it."