地学 dìxué earth sciences Origin Definitions Defs Strokes Stroke Words Sentences Sents 地 dì noun abbreviation of 地球 dìqiú the earth the earth; the planet on which we live; the third planet from the sun in our solar system学 學 xué noun abbreviation of 科学 科學 kēxué science science; scientific knowledge; a system of knowledge about the laws of nature, society, and thought