洋底地壳 yángdǐdìqiào oceanic crust Origin Definitions Defs Strokes Stroke Words Sentences Sents 洋底 yángdǐ ocean floor ocean floor; bottom of the ocean地壳 地殼 dìqiào earth's crust The solid outermost layer of the earth, composed of hard rock; it averages about 35 kilometers thick under continents and 7 kilometers under oceans.