noun

• In some bicameral legislative systems, the upper house or chamber.
• A group of experienced, respected, wise individuals serving as decision makers or advisors in a political system or in institutional governance, as in a university, and traditionally of advanced age.
• In Germany, the executive branch of government in the city states of Berlin, Bremen, and Hamburg; the governments of cities that were part of the Hanseatic League; and the bench in a higher appellate court.
• Any of several legislative bodies. (In countries which have multiple legislative bodies, the Senate is often the more senior.)
• (historical) The council that governed the ancient Roman Republic.
• (Canada) The Senate of Canada; the upper house of the Canadian parliament; "the Senate".
• (US) The United States Senate.
• (US) The upper legislative body of many of the states of the United States.