An ocean trench to the south-east of the Mariana Islands in the western Pacific, with the greatest known ocean depth (11,034 m, 36,201 ft at the Challenger Deep).
马里亚纳海沟（西太平洋马里亚纳群岛东南部世上最深的海沟）
Definition of Mariana Trench in US English:
Mariana Trench
proper noun
An ocean trench to the southeast of the Mariana Islands in the western Pacific Ocean. Its greatest known ocean depth is 36,201 feet (11,034 m) at the Challenger Deep, which was discovered by HMS Challenger II in 1948.