subduction
noun [ U ] geology specialized uk/sʌbˈdʌk.ʃən/ us/sʌbˈdʌk.ʃən/
（地球大陆板块边缘滑入另一板块下方的）俯冲，潜没
a situation in which of one of the earth's plates (= the large layer of rock that the earth's surface is made of) slides under another, often causing an earthquake or volcano