English language speakers generally use "American" to refer to the United States only, especially outside of Latin America; the same is true of cognates of the word in many other languages, such as the German Amerikanischer and the Greek Αμερικανός (Amerikanos). The CIA World Factbook lists "American" as both the noun and adjective forms of Nationality for a citizen of the United States.
As many people from the various nations throughout the New World consider themselves to be "Americans", some people think the common usage of "American" to refer to only people from the U.S. should be avoided in international contexts where it might be ambiguous. Many neologisms have been proposed to refer to the United States instead of "American". However, they are virtually unused, and most commentators feel that it is unlikely that they will catch on. See Alternate words for American for more information.
The American race is an obsolete 19th-century racial classification referring to the various peoples now called Native Americans, also historically called the "red" race, although that latter term is generally considered derogatory.