名詞 backbench:

1. any of the seats occupied by backbenchers in the House of Commons

back.bench

n.（名詞）
Chiefly British The rear benches in the House of Commons where junior members of Parliament sit behind government officeholders and their counterparts in the opposition party.
【多用于英國】 后座議員席：英下議院后排座的議員席，議會中職位較低的成員坐在政府官員和對立黨成員的后面
New members of Congress considered as a group:
議會新成員：議會的一組新成員：
例句：
.a revolt of the backbench fueled by a powerful lobbying campaign.(Washington Post)
.被強大的游說議員運動煽動的由新議員組成的反抗活動.(華盛頓郵報)

【引伸】
backbench.er
n.（名詞）