From Han 麥 to mugi, mil and mungi: one word, three loans, and why Proto-Japonic had *munki

Japanese mugi 'wheat, barley', Korean mil 'wheat' and Proto-Tungusic *murgi 'barley' have long looked like a shared Northeast Asian word. This note argues that their source is Old Chinese 麥 as spoken in the Han period, with its medial r still present (*mr-V-k), and that Japonic and Koreanic borrowed it separately, each by its own sound rules. Japonic most likely took the word in the first centuries AD on the Lelang – Iki – Kyushu route, where the earliest dated wheat in Japan is found (Iki, AD 127–233); the way Japonic took it supports Proto-Japonic *munki over *monki. Ainu mungi is a separate loan from the north, through Tungusic, with the barley of the Okhotsk culture (AD 440–890); a later loan from Japanese fits the form too. Beneath the loan lies a native plant word, reconstructed here as W-Oriensic *ᵐbəri. Weak points are listed with what would fix them.