Seattle has been wrapped in a thick gauze of fog for the past few days and I think it's starting to soak into my brain—I'm brain-fogged. Normally, sleep feels like a punctuation mark between moments of waking life. These days, it feels like the opposite. Consciousness is just an interruption of the real business of sleeping.
In honor of my lethargy, meet fog which, in about every other common-ancestor language, sounds like a word you can't say on the evening news:
fog (n.1) "thick, obscuring mist," 1540s, probably from a Scandinavian source akin to Danish fog "spray, shower, snowdrift," Old Norse fok "snow flurry," fjuk "snow storm." Cf. also Old English fuht, Dutch vocht, German Feucht "moist."
fog (n.2) "long grass," c.1300, probably of Scandinavian origin, cf. Norwegian fogg "long grass in a moist hollow," Icelandic fuki "rotten sea grass." The connection to fog (n.1), via a notion of long grass growing in moist dells of northern Europe, is tempting but not proven. Watkins suggests derivation from PIE *pu- "to rot, decay."
And Fogarty—as in John Fogarty of Creedence Clearwater Revival, who wrote some swampy/foggy music—comes from the Old Irish word fogartch, meaning "banished."
So "fog" might have some etymological roots in rot and decay. Strangely enough, the Oxford English Dictionary records the first written use of "fog" in 1380, in a poem called Cleanness that is attributed to the same person who wrote Sir Gawain and the Green Knight. Cleanness, in the tradition of old stories with deceptive names, is really about dirtiness and (according to Wikipedia because I can't read Old old English) "the delights of married love." The OED credits it with a ton of first-written-instance words: clustered, clat (to rattle or strike noisily), ringing, tarn (a small mountain lake), and so on. Anyway, the passage from Cleanness is:
He fares forth on alle faure, fogge watz his mete,
& ete ay as a horce when erbes were fallen;
Þus he countes hym a kow þat watz a kyng ryche
Whatever the hell that means. (Some guy eats everything, including fog, and thinks he's the king of the cows?)