two-party system

[ too-pahr-tee ]
/ ˈtuˌpɑr ti /

noun Government.

a political system consisting chiefly of two major parties, more or less equal in strength.

Origin of two-party system

First recorded in 1900–05

British Dictionary definitions for two-party system

two-party system

noun

a condition or system in which two major parties dominate a political unit