Cognate with江 (OC*kroːŋ, “river”) (Schuessler, 2007). The southern dialectal word originally meant "small river/stream", which is still preserved in someMin languages. The irregular pronunciation in Mandarin (expected Mandarin reflex is*jiǎng) originated from southern dialects where velars have notpalatalized (Schuessler, 2007).
李如龙[Li, Ru-long];刘福铸[Liu, Fu-zhu];吴华英[Wu, Hua-ying];黄国城[Huang, Guo-cheng] (2019), “港（～口）”, in莆仙方言调查报告 [Investigation Report on Puxian Dialect] (overall work in Mandarin and Puxian Min),Xiamen University Press,→ISBN, page258.
The traditional etymology that Japanese sources trace back to is a compound of水(mi-,“water”) +な(na,assimilatedapophonic form ofの(no,“genitive case marker”)) +門(to,“gate”).[3][4][5][6][7]
However, this does not correlate cleanly with the etymology of水(mizu,“water”), reconstructed asProto-Japonic*mentu(“water”). Then again, there are numerous attested words where水(mi) is used as the first and last element in compounds, suggesting either that the derivation of水(mizu) might differ.
Vovin, on the other hand suggests that the initialmi- was御(mi-,“honorific prefix”), while-na- meant "water", possibly fromProto-Tai*C̬.namꟲ(“water”).[8] Compare涙(namida,“tears”),菜葱,水葱(nagi,“Monochoria vaginalis”),漬く(nazuku,“soak in water”,obsolete).
However, this may present semantic difficulties, as any native formation likenamida that proposes "water" for the initialnam and "eye" for a following component reverses the usual word-formation pattern for Japanese, where the main or head noun comes last. In addition, thena element appears in other words with no relation to "water", as an assimilated apophonic form of genitive particleの(no), seen in terms such as掌(tanagokoro,“palm of the hand”, literally“hand's heart/center”),眼間(manakai,“where the lines of sight of the eyes converge”, literally“eyes' exchanging/crossing”).
”, in日本国語大辞典 [Nihon Kokugo Daijiten][2] (in Japanese), 2nd edition,Tokyo:Shogakukan,2000-2002, released online 2007,→ISBN, concise edition entry availablehere
