/uy'seuh lay"sheuh niz'euhm, is'euh-/ , n.
the policy or doctrine of isolating one's country from the affairs of other nations by declining to enter into alliances, foreign economic commitments, international agreements, etc., seeking to devote the entire efforts of one's country to its own advancement and remain at peace by avoiding foreign entanglements and responsibilities.
[ 1920-25, Amer.; ISOLATION + -ISM ]