Yes, and compare the sheer Paracelsian oddity of 'nostoc', also in the OED.

Here's the Gas official website - gas-mairie.info - which has no sign of etymology but does have a list of "Seigneurs de Gas" going back to a Gui de Gas born some time prior to 1220.

Here is the poem I wrote on
Friday, October 17, 2008

Best Left Said, As The World Seems Lonelier, and Still

Humility incarnates
the Aten
Humiliation / apple

dry vowel
wet sentence

weaving willow mandala
dormice station themselves
abuddha

a double
does these things
in the bardo
in the life of the bard
in the drab
and rabid pregnancy
impregnating
impregnable

imp's regent noble
gas; history of
chaos
so'chu

'the liquor of the box'

original mind
cannot be concealed
in vast rotary leaf displays
of mountain hermit
ferris wheels

snow monkeys
assemble
into elegant
living suits
of friendship

snow = noise
noise = matter

"What is the matter?"

[A tornado is also thinking here.]

so'chu [ah]
[ah] so'chu

a thing with thin strings
lies indiscernible among the trees

In André Pégorier, Noms de lieux en France - Glossaire de termes dialectaux, the closest term, geographically, to Gas would appear to be Gast, gât: friche, terre stérile, de médiocre valeur (Orléanais).

In the Wiki article on Degas the person who

"explains that De Gas was the spelling, 'with some pretentions, used by the artist's father when he moved to Paris to establish a French branch of his father's Neopolitan bank.'"

Occitan gas is, along with gaf, gal, etc., a variant of ga, cognate with French gué (m), "a ford". From Latin vadum (cf. English wade and possibly wash, Spanish vado) and crossed, says Petit Robert, with Germanic wad. Compare French surnames de Gué, du Gué, etc.

And English wath, in OED: "A ford; a fordable stream". Obs. exc. dial.; but there is a citation from 1894. Etymology:

[a. ON. vað neut. (MSw. vaþ, Sw., Da. vad) = OE. wæd (pl. wado), poet. the sea, the waves, MLG. wat (wad-), Du. wad, OHG. wat:—OTeut. *waðo-m:—pre-Teut. *wadho-m = L. vadum; cogn. w. wade v.]

And "Watt," the land between the mainland and the East Frisian islands in Germany, which is exposed during ebbtides.

We're definitely in Brichot territory; in fact, in the very passage I quoted here, I find: "Vieux comes as a rule from vadum, and means a passage, as at the place called les Vieux. It is what the English call ford (Oxford, Hereford)..."

compare the sheer Paracelsian oddity of 'nostoc', also in the OED.

What a word! And the OED says "With the ending, perhaps compare OPODELDOC n." Opodeldoc!!

I think you get quite a lot of extra points for having the word opodeldoc show up more than once in your blog, Language. Any idea about how to pronounce it, so I'll be able use it over Christmas? It might be good against hangovers.

(I'm assuming it's a poddle dock.)

And the Solway Firth was once Sulwath, much of it being fordable at low tide. Which relates distantly to the Dutch "g" which sounds to me like a thousand sea lochs being pronounced.

Any idea about how to pronounce it, so I'll be able use it over Christmas?

It's ahp-ǝ-DELL-dock.

So degas < decanus (cf. dean) is evidently unrelated. Did it lead to a surname too in the south?

From Latin vadum (cf. English wade and possibly wash, Spanish vado) and crossed, says Petit Robert, with Germanic wad.
This is clearly a variation on the Arabic "wadi", وادي‎ (a valley that floods during the rainy season), as revealed by the Arabic Etymological Journal of Irreproducible Idiopathic Inferences.

Ha ha, Nijma. Clearly! Yes, I thought about wadi myself.

Watt, vieux, and firth are all fascinating additions to this wordwhirl. Ford is close to fjord, and a whole spiral arm of words emanating from PIE per-.

I meant to make this clearer: firth (as for the old Sulwath), ford, and fjord are all closely cognate. Add port, fare, German -furt, and a zillion others for more remote connexions through PIE per-.

"Ford" and "Freud" (as in Sigmund) are also cognate, first documented in Aldous Huxley's Brave New World.

Opodeldoc, asafoetida, and treacle seem to belong in a set.

German -furt

Also exists as a separate word; not confined to place names.

David, I had thought so but did not check.

Opodeldoc, asafoetida, and treacle seem to belong in a set.

Hmmm. So then do gow, thebiac, and yen, somewhat differently.

"Ford" and "Freud" (as in Sigmund) are also cognate,...

O[de to] Joy! I'll see your Huxley and raise you one Joyce:

For opodeldoc, see also opopanax (famous as an ingredient of Molly Bloom's perfume, cf. μῶλυ, given by Hermes to Odysseus as a sovereign against Circe's enchantment, and a source of Molly's name).

Bloom, in the afterglow of his detached encounter with Gerty MacDowell:

Why Molly likes opoponax. Suits her with a little jessamine mixed. Her high notes and her low notes. At the dance night she met him, dance of the hours. Heat brought it out. She was wearing her black and it had the perfume of the time before. Good conductor, is it? Or bad? Light too. Suppose there’s some connection. For instance if you go into a cellar where it’s dark. Mysterious thing too. Why did I smell it only now? Took its time in coming like herself, slow but sure.

See also opobalsamum (citation in OED: "1844 Lingard Anglo-Sax. Ch. (1858) II. x. 113 The ignorance or experience of antiquity had ascribed to the opobalsamum the most salutary virtues").

"Why did I smell it only now?" Segue to Proust, now that we play strum of coincidence.

And theriac.

Yes, theriac. And I should have spelt mine thebaic. See also thymelic, thurific, theriodic, theandric, thymoleptic, and in the end (alas) thanatic.

One could go on. Theorically.

Theoretically, a brief history of thyme.

I'm really surprised Marie-Lucie hasn't come up with a theory of the etymology. I hope her computer hasn't broken.

Oppodeldoc [sic] is also used as a pseudonym by the narrator of Poe's superb burlesque The Literary Life of Thingum Bob. Here's a paper explaining the connections between patent medicine and literature which gives the etymology thus:

"Opodeldoc does, indeed, date far back, although not to Roman times as the tale implies, for 'Paracelsus' or Theophrastus Bombast von Hohenheim, the Swiss-German adept in alchemy and the Kabbala, coined the word as early as 1541. According to Kurt Peters, he composed it out of the italicized syllables in the three following ingredients for his medicinal plaster: 'oponax, bdellium, and aristolochia'", with the second d intrusive.

I'll add a link to my favorite anecdote about asafoedita.

Hmm, John Cowan. Oponax, opopanax, opoponax? OED has opoponax as a variant of opopanax, which must be regarded as better because of the -panax element being from πάναξ, from which we also get panacea. The first element is ὀπός ("vegetable juice"), which also yields opium. Opoponax is the only form in Ulysses, where it enables a reduplicative pun: ''Big comebig! Pirouette! Leopopold!'' But oponax? Hmmm. Late and spurious.

See also this:

http://books.google.com/books?id=DmYPAAAAYAAJ&pg=PA847&dq=opponax#PPA847,M1

A Dictionary of Archaic and Provincial Words, Obsolete Phrases, Proverbs, and Ancient Customs, from the Fourteenth Century
By James Orchard Halliwell-Phillipps, Lucy Cruikshank
Published by J. R. Smith, 1850
Item notes: v. 2 (J-Z)
Original from the New York Public Library
Digitized Oct 16, 2007

(Hey, the whole book can be downloaded!)

Late and spurious without doubt, Noetica, but also a splendid example of haplogy!

I herewith append the following canonical list of self-describing terms:

pyalatyalizyation, methatesis / metasethis, redup-reduplication, frikhathive, schwə, positionpost, teefoicink, anology, triephthouong, superlativissimus, diminutivito, ancicipation, rules of redundancy rules, reduced grud: zr grd : e grede : o grod, sekont sount shiftz, ebleut : ümläut, folk-entomology / folk ate-a-mology, frönting, voized, fəˈnɛtʰɪk, voized, suffix-ed, pre-fixed, epenethesis, rhotarism, haspʰiration, gemmination, apfrication, noun, noun phrase, adjectival, adverbially, conjunction and/or disjunction, "This is a complex sentence because it has a subordinate clause", genitive’s, gloʔʔalization, vowol harmono, to back formate, dithsimilation, anapityxis, execrescence, agglutinatinglanguages, apfricate, -pheresis, aphas...., diephthoung, kpoarticulated stop, compēsatory lengthening, condamination, diäeresis, díäçrît’ǐč, digræph, duplication, duplication, monophtong, nãsąlĩzątĩǫn, lharyngeal, mprenasalization, weagening or lenizhion, relick form, infuckingfixation, sibboleth, pro clitic, derivationalizationalize.

...vowol harmono,...

Ah John. I guffawed uninhibitedly at that one, for some reason.

But you left out ell[...]s. Or wait. No. Very smart!

And of course there are also lipgraphy and dittotography.