first-class ticket
Obsolete colloquial term for a first-class ticket, especially on trains. Modern Japanese uses 一等切符 or グリーン券.
In the old days, if you bought a first-class ticket, you could ride in a first-class car.
Compound of 白 (white, here implying first-class) and 切符 (ticket). The exact origin of using 'white' for first-class is uncertain, but it may derive from the color of the ticket or a traditional association of white with premium status.