Lower house
From NSWiki
The lower house, in politics, refers to the lowest chamber in a legislature that is bicameral, the other being the upper house. Characteristics and functions of such institutions vary widely, but generally the lower house in a parliamentary system wields more power, and in a presidential system will be of slightly less import.
Examples
The United Federation of Jenlom operates a bicameral legislature, with the lower house being referred to as the House of Commons.