shaft (n.2)youdaoicibaDictYouDict
"long, narrow passage sunk into the earth," early 15c., probably from shaft (n.1) on notion of "long and cylindrical," perhaps as a translation of cognate Low German schacht in this sense (Grimm's suggestion, though OED is against it). Or it may represent a separate (unrecorded) development in Old English directly from Proto-Germanic *skaftaz if the original sense is "scrape, dig." The slang sense of shaft (n.1) is punned upon in country music song "She Got the Gold Mine, I Got the Shaft," a hit for Jerry Reed in 1982.