köken: First attested in the Dongmun yuhae (同文類解 / 동문유해), 1748, as Early Modern Korean 검으스러ᄒᆞ다 (Yale: kemusule-hota). 거무스름 (geomuseureum) + -하다 (-hada, “to do”, light verb deriving adjectives).
köken: Inherited from Old Czech smědý (where m changed into n probably because of the resemblance with hnědý (“brown”)), from Proto-Slavic *smědъ, whose origin is ambiguous. It might come from Proto-Indo-European *směh₁- (“to dirty”).
köken: Uncertain. Traditionally derived by the Romans from aqua (“water”), which is supported by Pokorny, who also adduces Aquilō (“the North wind”) as related. Though the above theory is rejected by Ernout and Meillet, De Vaan finds it preferable to an alternative derivation from aquila (“eagle”) suggested by Cohen 2004: 32.