A senate is a deliberative assembly, often the upper house or chamber of a bicameral legislature. The name comes from the ancient Roman Senate, so-called as an assembly of the senior and therefore considered wiser and more experienced members of the society or ruling class. However the Roman Senate was not the ancestor or predecessor of modern parliamentarism in any sense, because the Roman senate was not a de jure legislative body.

An upper house is one of two chambers of a bicameral legislature, the other chamber being the lower house. The house formally designated as the upper house is usually smaller and often has more restricted power than the lower house. A legislature composed of only one house is described as unicameral.