norm (n.)youdaoicibaDictYouDict[norm 词源字典]
"standard, pattern, model," 1821, from French norme, from Latin norma "carpenter's square, rule, pattern," of unknown origin. Klein suggests a borrowing (via Etruscan) of Greek gnomon "carpenter's square." The Latin form of the word, norma, was used in English in the sense of "carpenter's square" from 1670s.[norm etymology, norm origin, 英语词源]