1historical, rare Of, relating to, or designating the North American territories which were colonies of the Russian Empire, especially during the 19th cent. In later use chiefly in "Russo-American Company".
2Of, belonging to, or involving both Russia (or the former Soviet Union) and the United States of America; of mixed Russian and American origin.
Early 19th century. From Russo- + American. Compare German russisch-amerikanisch, French russo-américain, both earliest in sense 1.