A person with an American Serviceman, either Civilian or Military, of ANY ethnicity or nationality for a father and an Asian or Pacific islander for a mother; the offspring, child or direct descendant of such a relationship, whether married or unmarried. Also: in very rare occasions the genders of the parents may be reversed, i.e. the product of an American servicewoman and Asian male.
Literally, American + Asian = Amerasian
His father was an African-American soldier and his mother was Korean woman. See the main character of the book SNOW CRASH by Neal Stephenson.