英语词源字典 - 在线词源网站

groundwork (n.)[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]
mourn (v.): Old English murnan "to mourn, bemoan, long after," also "be anxious about, be careful" (class III strong verb; past tense mearn, past participle murnen), from Proto-Germanic *murnan "to remember sorrowfully" (cognates: Old Saxon mornon, Old High German mornen, Gothic maurnan "to mourn," Old Norse morna "to pine away"), probably from PIE root *(s)mer- "to remember" (see memory); or, if the Old Norse sense is the base one, from *mer- "to die, wither." Related: Mourned; mourning.
walk (n.): c. 1200, "a tossing, rolling;" mid-13c., "an act of walking, a going on foot;" late 14c., "a stroll," also "a path, a walkway;" from walk (v.). The meaning "broad path in a garden" is from 1530s. Meaning "particular manner of walking" is from 1650s. Meaning "manner of action, way of living" is from 1580s; hence walk of life (1733). Meaning "range or sphere of activity" is from 1759. Sports sense of "base on balls" is recorded from 1905; to win in a walk (1854) is from horse racing (see walk-over). As a type of sponsored group trek as a fund-raising event, by 1971 (walk-a-thon is from 1963).