köken: From Proto-Vietic *-jəm (“black, dark”). Cognate with Muong Bi dầm (“black”), Mon ယောံ, Mal ɲam ("black"), Phong-Kniang jam ("black"). Attested as nhâm and dâm in the Dictionarium Annamiticum Lusitanum et Latinum (1651). The unusual onset change is most likely due to the taboo of mentioning dâm. Compare dâm bụt (“hibiscus”). Genetically unrelated to Thai ร่ม (rôm) and Chinese 陰 (MC 'im) (SV: âm)…