Demonym
The demonym for people of the United States of America has a similar problem. "American" can mean either someone from the United States, or someone from any part of American region or the two American continents (North America and South America). United Statian is not frequently used in English, but it exists. It is commonly used in Spanish (estadounidense) and widely used in Latin American Spanish. French (étatsunien(ne)) exists but is rarely used, Portuguese (estado-unidense or estadunidense) but it is not as commonly used, Italian (statunitense) exists but is rarely used, and also in Interlingua (statounitese). In Esperanto the country is Usono and the demonym is Usonano, avoiding confusion with Amerikano. US American (for the noun) and US-American can be used but is not widely used in German (US-Amerikaner'').