nunyoudaoicibaDictYouDict[nun 词源字典]
nun: [OE] In medieval Latin, nunnus and nunna were titles of respect accorded respectively to old men and old women in general. In due course they came to be applied specifically to ‘monks’ and ‘nuns’. The masculine form has since disappeared, but the feminine nonna was borrowed into Old English as nunne. This was subsequently reinforced in the 13th century by Old French nonne.
[nun etymology, nun origin, 英语词源]
nun (n.)youdaoicibaDictYouDict
Old English nunne "nun, vestal, pagan priestess, woman devoted to religious life under vows," from Late Latin nonna "nun, tutor," originally (along with masc. nonnus) a term of address to elderly persons, perhaps from children's speech, reminiscent of nana (compare Sanskrit nona, Persian nana "mother," Greek nanna "aunt," Serbo-Croatian nena "mother," Italian nonna, Welsh nain "grandmother;" see nanny).