洋脊 yángjǐ oceanic ridge Definitions Defs Origin Strokes Stroke Words Sentences Sents 中大西洋脊 zhōngdàxīyángjǐ mid-Atlantic ridge the mid-Atlantic ridge中洋脊 zhōngyángjǐ mid-ocean ridge a vast undersea mountain system formed by plate tectonics, spanning the Atlantic, Indian, and Pacific Oceans