sandman (n.)youdaoicibaDictYouDict[sandman 词源字典]
bringer of sleep in nursery lore, 1861, from sand (n.) in reference to hard grains found in the eyelashes on waking; first attested in a translation from the Norwegian of Andersen (his Ole Lukoie "Ole Shut-eye," about a being who makes children sleepy, came out 1842), and perhaps partly from German Sandmann. More common in U.S.; dustman with the same sense is attested from 1821.[sandman etymology, sandman origin, 英语词源]