Abbreviation for "American Born Chinese".
A child who is born in America and has two Chinese parents born in China. Their parents usually push them too hard because they were born in America and not China. They usually sign them up for piano and/or violin, computer and/or math clubs, Chinese school, and usually not sports. The ABC's parents don't let them have any friends and acquaintances, and whenever they are in public, they look ashamed to have them as a child.
Guy on the street in Chinatown: IS YAW SUN ABC?
ABC's parent: *nods silently*