Literally: “test rabbit” / meaning: “guinea pig” (for an experiment)
You were stupid enough to brag about your cooking skills on Tinder. Tomorrow your date is coming to visit. So you download the first recipe you find on the web.
Since you don’t want to make a complete fool of yourself, you need someone to try out the recipe on. Therefore, you invite a friend to be your test eater—or your Versuchskaninchen, for that matter. Just like its English counterpart, guinea pig, you will hear the word quite often in everyday situations that have nothing to do with actual experimentation labs. It has been around at least since the 1860s, but it’s safe to assume that rabbits have had to undergo dubious treatments even way before, I’m afraid.
In this regard, the English version beats the German expression in terms of accuracy. According to the US Department of Agriculture, there were 171,406 guinea pigs used in American laboratories vs. 133,634 rabbits in 2019. These figures are not something humanity should be proud of.