noun
parliamentarian; member of a congress; Diet member
Specifically refers to a member of the Japanese National Diet (国会), though it can be used for members of other national legislatures in translation. In Japanese political context, it is a formal title for elected representatives.
彼は地元選出の代議士として長く活動している。
He has long been active as a Diet member elected from his local district.
The Diet Members' Office Building houses many parliamentary offices.