Germany

Schadenfreude

Zeitgeist

Kindergarten

I prefer English words making it incorrectly into German. "Getting a handy from your buddy at a public viewing" is totally innocent in German.

My friend in Australia is a doctor studying psychiatry and he kept asking me what certain worlds meant and half the time I had no idea what they were or how to explain them lol.

Very random. Here's a wiki list but I remember there were some others too

Anwesenheit

Dermatozoenwahn

Entgleisen

Gedankenlautwerden

Mitgehen

Mitmachen

Pfropfschizophrenie

Schnauzkrampf

Wahneinfall

Verstimmung

vorbeigehen; vorbeireden

Witzelsucht

Würgstimme

Word salad/Wortsalat

Zeitraffer

Zeitlupenwahrnehmung

It's kind of interesting to see the long lasting effect of Germans pioneering the medical field for a very brief time in history.

I think doppelgänger is the most spread one.

Gesundheit

Poltergeist

Spiel

Stool ( Stuhl )

Rucksack

Zeitgeist

Spiel

Schadenfreude

Kindergarten

Iceberg

For the chess people: Zugzwang and Zwischenzug!

Eigenvalues and eigenvectors, which however, were not discovered by the well known mathematician Eigen. Ansatz ist also commonly used in research articles.

Gift. No wait

I guess mine would be kaput

(German) Angst Apfelstrudel Kindergarten Oberlichte ...

Bremsstrahlung

Meister

Gestalt

Halt!

In mathematics:

Eigenvektor

Zugzwang

Abseil.

Abseiling

Doppelgänger

Weltschmerz

Nagelbrett. https://coenbrothers.fandom.com/wiki/Nagelbett

"Ouch"

Does "Neuschwanstein" count? As in the castle in bavaria. Because I find it amusing how native english speakers just stumple over the pronounciation. Also "Gesamtkunstwerk" because it seems kinda superflous.

“Fuck”