What Is a Country's Main Legislative Body Called?

The primary lawmaking body goes by different names depending on the political system: legislature (generic), parliament (Westminster systems, e.g., UK, Canada, Australia), congress (presidential systems, e.g., USA), diet (Japan), duma (Russia), bundestag (Germany), national assembly (France, South Korea), and others. Bicameral systems have two chambers (e.g., Senate + House); unicameral systems have one.