isolationist adjective 1noun 1forms 3 adjective1 •Relating to, or supporting, isolationism.You’re basically seeing with Netanyahu what Trump wished he could have done. America has an isolationist bent right now, we don’t want to get involved in boots on the ground warfare. — 2024 noun1 •One who advocates or supports isolationism. formsisolationists · more isolationist · most isolationist