What does it mean?
“Stinksauer” simply means “really really angry”, although literally it means “stink-sour”. “Stink” (somewhat obviously meaning stink) is meant to act as an intensifier. A synonym of it is “Stinkwütend” or “die Stinkwut” (meaning the extreme anger).
What are its origins?
The second half of the word “sauer” literally means sour, but to say that someone is “sauer” means that they are angry. This is somewhat similar to English, as someone can have a “sour demeanour."
The use of the word “sauer” as a word for angry (or wütend in German) dates back to the Middle Ages, where the phrase “Jemand sauer ansehen” (to look at someone sourly) was widely used.
However “Sauer auf jemanden zu sein” (“to be angry at someone”) emerged only at the beginning of the 20th century. The word stink was added as a negative intensifier. This was applied to various adjectives such “reich” (meaning rich, so stinkreich would mean someone were very rich) and “normal” (meaning normal, “stinknormal” used in the context of meaning of extremely average boring).
The first written use of Stinksauer is said to date back to the early 70s.
How is it used?
Stinksauer is used as an adjective to describe someone who is extremely angry. It is used across Germany, and by virtually all age groups. It isn’t exactly a curse word, and it isn’t necessarily Umgangssprache, or slang, but it is generally used informally.
Uses of Stinksauer
Simon ist stinksauer mit seinem Chef.
Simon is really angry at his boss.
Also sowas macht wir wirklich stinksauer!
Well, something like that really makes me mad!
Wenn jemand mir nochmal versucht, das Handy zu klauen, dann werde ich stinksauer!
If someone tries to steal my phone again, I’m going to get really pissed.