お疲れ様 (good job+"you look tired"+"I an acknowledging this and presenting recognition of your effort")

Keigo modifiers. ご覧 vs 見る. They both mean "look". One is, somehow, more polite.

Kansai dialect. しばいたろか ("wanna get smacked?" but it's playful) or まいど ("thanks" but also "nice to see you again" and "hello" but only in specific contexts between specific people. Mess it up and you'll probably hear the other Kansai term previously described.)

झूठा खाना/पानी (Jhootha khana/pani)

Food/water that is cosumed by someone else and hence is unsuitable for eating/drinking. Especially for religious or devotional rituals.

In the similar vein, https://en.wikipedia.org/wiki/Prasada

Sisu. Its a mix of courage, determination, resilience, keeping your nerve, doing a scary or difficult thing even though you know that odds of succeeding are low. Its also done quietly, no complaining or boasting about it. You can mutter some curse words quietly to yourself.

Closest English word for it might be "guts" or "grit". But those don't really explain it completely.

Finnish.

Javertus. (Danish)

It's a thing that sticks out, and you don't know what it is, but it has the function of sticking out. Like a naturally occurring bulgy peak or other unknown long shape coming out of something else.

It's most often used as slang for penis, but otherwise it might be found on trees or wooden objects.

Gezellig in Dutch. Used to describe a situation that's cosy and fun togetherness. Can also be used to describe a place that looks inviting (to have that good time in). I guess 😃

Fjøs is where farm animals are kept. "Barn" is more general and translates to "Låve", while Fjøs doesn't really have an English translation.

Nisse is a mythological creature that is part goblin, part santa, part Gnome, but not really either of them. They're usually benign and pretty cool.

Hygge (noun) /hyggelig (adjective) means having a cosy, lighthearted or fun atmosphere, usually in company of others

EDIT: By the way, Nissen lives in the Låve

Russian is more productive than English, so there's a bunch of "we just smushed a bunch of prefixes and suffixes on it" words that don't have a great English equivalent, like недоперепить -- to drink quite a lot but not succeed at drinking too much. I don't think we properly have листопад which is the equivalent of "snowfall" but for autumn leaves. I really miss успевать -- to successfully have enough time to do something. There's also кипяток -- water that has been boiled but then slightly cooled, like 200-205 degrees F. The canonical examples are тоска , which is a kind of melancholy longing, and авось which expresses optimism but I basically never heard anyone actually say.

In Spanish.
Sobremesa, the period you stay at the table after lunch or dinner having a coffee or some drinks while chatting.

Aprovechar, is basically the opposite of to waste. So depending on the context is to take advantage of something, to make the most of, make a good use, give a second use or reuse leftovers for something else.

In JavaScript, this.

Guten Appetit! (German term equivalent to "cheers" for drinking - but for eating.)

Shaka, when the walls fell

Does it count if English just steals your words?

Schadenfreude, Zeitgeist, Weltanschauung, Kindergarten.

Hinh in Burmese. The closest equivalent is curry, and while all curries are hinh, not every hinh is curry. It basically means something you eat with the rice.

Lanche, the meal between lunch and dinner

Bukkake.