Not unknown in the US, though? I seem to remember it’s referred to in Bessie Smith’s Kitchen Man - though perhaps a different sort of sausage 
If Bologna points to Italian origins, might Polony be a reference to Polish sausage?
Surely they’d heard of “polony”?
ETA - damn, too slow.
No, it’s just a variant of bologna - same as “baloney”
In Australia this is variously known as Devon, Fritz, Belgium, Polony or Luncheon meat in various states. Before WWI it was mostly called German Sausage, so perhaps the multitude of names are just clumsy local attempts to rename it to avoid association with the then enemy, as with the Alsatian dog.
Speaking as neither a Yank nor a Brit, I have to say that the term “lunch meat” is deeply, deeply unappetizing. It sounds suspiciously vague and oddly institutional.
From the Wikipedia entry:
Lunch meats—also known as cold cuts, luncheon meats, cooked meats, sliced meats, cold meats, sandwich meats, delicatessens, and deli meats—are precooked or cured meats that are sliced and served cold or hot. They are typically served in sandwiches or on a tray. They can be purchased pre-sliced, usually in vacuum packs, or they can be sliced to order, most often in delicatessens.
In my area “cold cuts” is probably the most common label for the category. The type of meats you would find in a deli platter, which you might find at pretty much any gathering where light food is being served:
Yeah, back when I was living in New York in 2000-2002, I would have called them “cold cuts” or “deli meat”.
If you’re posh, it’s "charcuterie’
If you’re not posh, it’s Spam.
Seriously, Spam is what I think of when I think “luncheon meat,” though “deli cold cuts” would do just as well. Any kind of meat that can be served between two slices of bread qualifies. Ham or salami or roast beef and cheese and tomato on a kaiser roll for me, though a couple of slices of Spam and cheese and tomato on a kaiser roll is just as good. They’re all luncheon meats.
It’s a bit like the Astronomy version of ‘metal’ (everything that isn’t Hydrogen).
In this case though, it comes from the latin ‘metallum’, meaning crushed rock including, but not limited to, mined metal ores. Roads were one thing the Romans did for us.
Never heard someone called a “berk”? Comes from “Berkeley Hunt”, and you can probably guess the referent.
…or Helium (inb4 nitpicks)
You’re actually correct. It sells because it’s cheap, and served in school cafeterias and jails.
Irrigation?
Yes. I’ve heard loads, but just can’t think of the examples.
Well yeah, obviously irrigation.
Hah! So that’s what that line was? I always heard it as a “fried-out zombie” which really made me wonder.
Another one I heard again recently:
syrup [of fig] = wig
And did we have:
Rabbit [and pork] = talk
Spam is an elevated meal if you fry it, whereas lunch meat is served as-is.
“Zombie” is in the next line that rhymes with it. It apparently means cannabis.
It doesn’t have to be cheap. I consider any kind of deli meat “lunch meat,” and that includes roast beef and pastrami that sells for like $10/lb and more.
In a “class” switch, “lunch meat” can be deli and expensive. “Luncheon meat” is inevitably canned and less than stellar. Although I have a weak spot for fried Spam and eggs as a camping breakfast.