Does anyone know the origin of the word "smithereens," as in "The tornado blew the trailer to smithereens?"

smithereens” comes from an Irish
word, “smidirin,” meaning “small fragments, atoms,”

From www.takeourword.com, issue 50
Almost any word that ends with -een can be assumed to
be Irish and smithereens is no exception. The -een
suffix represents the Irish diminutive -ín as in colleen "a
young girl", boreen "small road" or "lane", kippeen "a
small stick". A smithereen is a smidirín in Irish. The only
problem with this is that Irish has no word smidir.
Smidirín is thought to be the diminutive of the English
word smither, a word with no known origin which means
just the same as smithereen.

And you mustn't forget poteen, a bit of the good stuff.

How 'bout soup tureen?

MW:

"Main Entry: tu·reen
Pronunciation: t&-'rEn, tyu-
Function: noun
Etymology: French terrine, from Middle French, from feminine of terrin of earth, from (assumed) Vulgar Latin terrinus, from Latin terra earth -- more at TERRACE
Date: circa 1706
1 : a deep and usually covered bowl from which foods (as soup) are served
2 : CASSEROLE 1

The history bookis forget to mention it, but the biggest tragedy of the Potato Famine
was loss of poteen.

Now Bill, with people dying of starvation in their thousands and hundreds of thousands more going to wild, uncivilised places like North American between 1845 and 1850, why do you think that the loss of a bit of booze didn't get so much as a dishonourable mention in the history books?

Dear CK: you remind me of a gag by Red Skelton in movie about Alaska Gold Rush.
A guy comes back from a weeklong trip for supplies. He has thirteen bottles of
whiskey, and a loaf of bread. Skelton demands: "You goddam fool, what are we
going to do with all that bread?"

Almost any word that ends with -een can be assumed to
be Irish

This is throwing down the gauntlet, Bill.

-teen numbers immediately spring to mind, though there the derivation is (fairly obviously) from OE for ten.
I'm sure more "exceptions" will be forthcoming...

the English word smither, a word with no known origin which means just the same as smithereen.
Never heard this one, though maybe that's not surprising if it's an old term. But I wonder aloud if "smithers" were odd little bits of metal left around by the work of a smith ? Does anyone know if odd little bits of metal would be left around by a smith?

That would appear to fit the meaning very well.

anyone know if odd little bits of metal would be left around by a smith? Not really bits of metal, but particles of oxydised iron from the black layer that forms on the surface, fly about in the forge when the smith pounds on the red-hot workpiece.