马里亚纳海沟 mǎlǐyànàhǎigōu Mariana Trench Origin Definitions Defs Strokes Stroke Words Sentences Sents 马 mǎ phonetic 里 lǐ phonetic 亚 yà phonetic 纳 nà phonetic 海沟 海溝 hǎigōu oceanic trench A long, narrow, and steep-sided depression in the ocean floor, typically exceeding 6,000 meters in depth.