英语词源字典 - 在线词源网站

foggy (adj.)[foggy 词源字典]: 1540s, of the air, "full of thick mist," perhaps from a Scandinavian source, or formed from fog (n.1) + -y (2). Foggy Bottom "U.S. Department of State," is from the name of a marshy region of Washington, D.C., where many federal buildings are (also with a suggestion of political murkiness) popularized 1947 by James Reston in "New York Times," but he said it had been used earlier by Edward Folliard of "The Washington Post."[foggy etymology, foggy origin, 英语词源]
murk (n): c. 1300, myrke, from Old Norse myrkr "darkness," from Proto-Germanic *merkwjo- (cognates: Old English mirce "murky, black, dark; murkiness, darkness," Danish mǿrk "darkness," Old Saxon mirki "dark"); cognate with Old Church Slavonic mraku, Serbo-Croatian mrak, Russian mrak "darkness;" Lithuanian merkti "shut the eyes, blink," from PIE *mer- "to flicker" (see morn). Murk Monday was long the name in Scotland for the great solar eclipse of March 29, 1652 (April 8, New Style).
murky (adj.): mid-14c., from murk + -y (2). Rare before 17c. Related: Murkily; murkiness.