noun
Refers to the upper house of a legislature, such as the U.S. Senate or similar bodies in other countries.
上院議会は法案を可決した。
The Senate passed the bill.
下院議会 is the lower house (e.g., House of Representatives), while 上院議会 is the upper house (Senate).
Compound of 上院 (upper house) and 議会 (parliament, congress).