Colloquial Italian has a word, "paturnia", probably stemming from Latin "pati" (to suffer), which is used meaning just "commotion or fuss", or "mental turmoil". Could "pother" be a corruption of "paturnia", brought to the U.S. by Italian immigrants?

Probably not. OED traces it back to early 16th century with the earliest definition being 'a choking smoke or atmosphere of dust.'

Pother is definitely English. It certainly describes the state one of my client put me in today.

Welcome, Tony. Say hi to Giacomo for me!

Online etymology brings these two words together:

pother
c.1591, "disturbance, commotion," of unknown origin. Meaning "mental trouble" is from 1641; verb sense of "to fluster" is attested from 1692.
bother
1718, probably from Anglo-Irish pother, since its earliest use was by Irish writers Sheridan, Swift, Sterne. Perhaps from Ir. bodhairim "I deafen." Related: Botheration (1797); bothersome (1834).

Would possibly "bodhairim" and "paturnia" have any connection?

I am not an expert on Celtic etymology, but I know that the origin of "paturnia" from Latin "pati" is not proven, and I also know that many Northern Italian words have Celtic origins, so I would not reckon a relationship between "bodhairim" and "paturnia" as totally impossible.

many Northern Italian words have Celtic origins Really? How come?

Same place as those blue-eyed, blond-haired northern Italians... :0)

I thought those were Goths. But seriously, the languages were right smack up against each other for a long time and the Celts came within a gnat's butt of successfully invading the Italian peninsula.

That said:

A) The Celtic language spoken by Asterix's people and Old Irish were probably mutually incomprehensible and we have no reason to believe that any word with a similar meaning and a similar sound to the Irish bodhairim would have existed in the continental Celtic language.

and

2) The influence on the language would have been on Latin anyway, so we're still back to paturnia coming from something in Latin.

Could "pother" be a corruption of "paturnia", brought to the U.S. by Italian immigrants?

The first citation for the noun pother, in the sense of 'commotion', in the OED1 is 1592. Words that get adopted into one language from another usually undergo some kind phonological transformation in that sounds in the original language (in this case Italian) that don't exist in the target language (English) get modified. I am not aware of any words in English of Italian origin where a /t/ became a /ð/. Overall, I say no.

I am not an expert on Celtic etymology, but I know that the origin of "paturnia" from Latin "pati" is not proven, and I also know that many Northern Italian words have Celtic origins, so I would not reckon a relationship between "bodhairim" and "paturnia" as totally impossible.

Most of the Italian etymologies I looked at link Italian paturnia (or paturna) 'sadness, melancholy; bad mood' to a Greek loanword from παθος (pathos) 'incident (good or bad), accident' < the verb πασχω 'to suffer'; the Greek word is related to Latin patior 'to suffer'.

As for northern dialects of Italian, I find a few references to Milanese patocch adj., paturgna n. (link), but also to Neapolitan a patùrniè (link). So, I'm not sure it's just northern Italian.

Though, the word is not recorded in Latin, the suffix -urn- does exist: e.g., diurnus 'by the day, of the day' from dies 'day', alburnus 'a kind of white fish' from albus 'white', eburnus 'of ivory' < ebur 'ivory'. In fact the melancholy Roman God Saturnus shares this suffix.

As for the Celtic languages spoken in the Italian peninsula, I would not choose Irish. There were several monasteries in Northern Italy founded by Irish monks, Bobbio comes to mind, but there were other non-Goidelic Celtic languages that are poorly attested, that seem more likely to have been Continental (Gaulish). In fact, some scholars see Lepontic as a Gaulish dialect spoken in Rhaetia and the Cisalpine region. It's really a question of when the word came into Italian and whether it came from Medieval monks speaking Old Irish or some pre-Italic (and possibly Celtic language) of Northern Italy. (And not all pre-Italic languages in Northern Italy were Celtic. Ligurian, for example, is not even thought by some to have been an Indo-European language. Old Irish bodar 'deaf' has a Welsh cognate [i[byddar[/i]. I don't quite follow how Old Irish went to Italian and then was borrowed into English. Or are you saying that Old Irish provided loanwords to both Italian (bodar > paturnia > pother) and English (bodar > bother)?

You would have to study the history of paturnia in Italian. I would also look at a Medieval Latin dictionary (Du Cange) to see if there was a Medieval Latin word that was similar.

I don't know, could it be Dutch? ...Dutch, "peuteren": to rummage, poke. Since this first appears by Irish writers like Sheridan and Swift could this word be a product of the vowel shift when the William of Orange became King of England?

I was put in a pother by my brother, who at the request of mother, roused me from slumber by being a bother.

Interesting. Gaulish. Goidelic. Gealic. Celts must have covered quite a lot of different locations. From your links I noticed in the Venetian, Piacento and Padova dialects something like 'aver la luna', ave la lune, le lune ? Something with the the moon?
Nice wordlists!

William of Orange has had some up till these days bothersom effects on Northern Ireland, but nothing to do with this word I guess. I traced some Dutch etymology of peuteren. Translated the part under the second 'peuteren' to my best possibilities.

Link

'peuteren' verb. Kiliaen peuteren, pöteren stands with the under 'peuren' mentioned pod(d)eren, compare with potersam, 'bothersom , difficult'.
The word formally belongs as iteratief(?) to 'poten', but forms with pöderen a wordgroup with a strong affectif character. - much older than Kiliaen, because in the 12th century colonists have taken the word to the Brandenburger Mark paetern 'to pick fruits beating with a stick; nose picking.
( Teuchert Sprachreste 284 )

( Don't know what you can make of it, Jim.)

peuteren

I have the sam eobjection as to the paturina to pother conecture. Why did a /t/ turn into a /ð/? In fact it makes sense, if you posit a Proto-Germanic root that yielded pother in English and peuter(en in Dutch.

Celts must have covered quite a lot of different locations.

Yes, they got around. There are Galicias in NE Spain and in Anatolia; Iberia in Europe and Caucasus. Not sure they were the same ethnicity, nor even if they spoke a Celtic language. There is a field of anthropology called Celtomania, and its opposite, Celtoscepticism. Yes, I noticed the aver le lune, literally, 'to have the moons'.