unamerican

Un-American describes attitudes, behaviors, or activities perceived as contrary to American values or interests.

The term is inherently political and shifts meaning depending on who wields it—Cold War anti-communists called socialist ideas un-American; critics of xenophobia call border policies un-American.

The House Un-American Activities Committee investigated suspected communists.

The charge implies disloyalty or foreignness, often deployed to delegitimize opponents rather than describe actual citizenship status.