groundwork (n.)youdaoicibaDictYouDict[groundwork 词源字典]
mid-15c., "foundation of a building or wall, solid base on which a structure is built," from ground (n.) + work (n.) in the older sense. Similar formation in Middle Dutch grontwerck, Dutch grondwerk, German grundwerk. Of immaterial things from 1550s.[groundwork etymology, groundwork origin, 英语词源]