mother of pearl (n.)youdaoicibaDictYouDict[mother of pearl 词源字典]
c. 1500, translating Medieval Latin mater perlarum, with the first element perhaps connected in popular imagination with obsolete mother (n.2) "dregs." Compare Italian madreperla, French mère-perle, Dutch parelmoer, German Perlmutter, Danish perlemor.[mother of pearl etymology, mother of pearl origin, 英语词源]