run-of-the-mill 词源(Etymology) - 趣词词源[英文版]

run-of-the-mill (adj.)[run-of-the-mill 词源字典]: "unspectacular," 1909 in a literal sense, in reference to material yielded by a mill, etc., before sorting for quality (compare common run "usual, ordinary type," from 1712). Figurative use is from 1922.[run-of-the-mill etymology, run-of-the-mill origin, 英语词源]