Spomenik simply means monument in Croatian/Serbian, but in the english language context, I saw spomeniks specifically referring to the bizarre futuristic memorials from the Balkans, now decaying. There’s at least half a dozen various articles/list on the web, here’s one.
For that matter, most of these terms seemed to have entered general American English parlance quite a while before jumping across the pond. First I heard of a jalapeno was in Eddie Rocket’s (Irish fast food chain) circa 2000.
Thankfully, it largely vanished from mainstream slang just as quickly. I haven’t heard it used since Ali G went off the air (although “poontang” and “poon” remain in use in cruder circles).
Likewise, mockney TV chef Jamie Oliver made “pukka” popular with the wider UK population in the 1990s, another fad that has fortunately faded.
It’s also been around for well over 16 years - I was aware of the term as the French equivalent of “Frog” (mildly derogatory, but in an unmenacing way) in the mid-late 90s, and that was in New Zealand.
Oddly enough in the Irish language the word for a French person and a rat is the same, “francach”.
And speaking of French, how recently did the term “parkour” start being used in English?
Google’s Ngram has it starting to appear in English books in 2000.
What?! [checks] Poot, “bread babies” was such a cute idea… 
“Pan” is Japanese for bread and everyone agrees it comes from Portuguese. Perhaps there was some later Spanish influence that lead to the “pan” pronunciation? Or maybe the Portuguese pronunciation was closer to “pan” in the 16th century?
Different word, same pronunciation. Your mook. My mook.
It’s already pretty close. It’s a very nasal vowel, so the Portuguese word for “bread” sounds a lot like “pow…n”.
And Japanese generally don’t pronounce a terminal “n” the way we do (or the Spanish do) anyway. It’s a bit nasal.
In my childhood in the 80s in Ohio (so, reasonably far from Tex-Mex land), we knew of jalapenos. Of course, we knew them as “that really, really hot pepper that a person would be a fool to actually eat”. They occupied much the same space in popular consciousness that habaneros do now.
Thankfully, I’ve since learned better.
When did jalapenos with nachos become a thing? I guess I did really start going to movies until the late 80s (which is where I had most of my nacho consumption), but I can’t remember a time when they came without the option of pickled jalapeno slices. Then again, I also live in Chicago which has a significant Hispanic population.
Chevron gas stations had a Hawaiian-themed promotion in the '60s offering Wiki-Wiki Dollars. And according to that link, “wiki” turns out to be one of those borrowed-back words, as the Hawaiian word is itself a corruption of the English “quickly.”
What about words from the artificial languages in Game of Thrones? Since the HBO series has been a huge hit, have any of those words gained currency in English? I know if I said “Khaleesi” to many of my friends, they’d know exactly what I was talking about. And then there’s “Frack” from BSG on ScFy channel.
Dictionary.com says Ward Cunningham was using “WikiWikiWeb” in 1995.
I would think that if any words have entered English from a language that was made up for a book, it would be from Tolkien or Rowling rather than Martin.
Or George Orwell, if you consider Newspeak to be a language made up for a book. Newspeak gives us (among others) doublethink, unperson and thoughtcrime, as well as new senses for existing words (e.g. “rectify” in the sense of altering a historical record to show what is now desired to be shown).
Anthony Burgess created Nadsat for A Clockwork Orange, but offhand I can’t think of any Nadsat words which have made it into vernacular English.
Plenty of words coined by Lewis Carroll survive and thrive outside the texts he created them for (e.g. galumph), but they aren’t from a created language. And of course there are plenty of common words that either were coined by, or are first recorded as used by, William Shakespeare.
Horrorshow (“good”) is rare but appears occasionally, although some usage may just be an elision of “horror show” (especially the couple of uses before 1962 when Clockwork Orange was published).
According to theOED, words from Tolkien that now appear in it include hobbit, mithril, orc, and mathom (although the last two were revivals of Old English words.
I suspect it’s a confusion between “coming from Portuguese” and “coming from the Portuguese”. I’ve seen the same issue with Spanish words being identified as “Portuguese roots” in Japanese a few times before; they are always from back when mixed crews were extremely common, partly due to who was king of Portugal at the time. I’m not sure what would be his appropriate numeral for the Crown of Portugal, but in English he’s usually known as Phillip II of Spain.