This is part of a friend’s email - “Apparently “kalsarikannit” in Finnish means - ‘to get drunk at home in your underwear’. My phone google doesn’t translate it at all so that may be a hoax”.
Not a hoax but for those interested, a learned explanation of the meaning can be found here - http://thusspoketero.blogspot.com/2017/06/no-that-is-not-what-kalsarikannit-means.html
One of my favourites is a French one - ‘le qu’en dira-t’on’, which roughly means ‘the what would the neighbours say’. It was said to me about one of my cars, and I enjoy the idea of ‘anti-keeping-up-with-the-Joneses’.
Huh?
Then there is the French expression to describe the tasty brown meat on the underside of a chicken - the fool leaves it - le sot l’y laisse.
“slaapkamer” the Dutch for bedroom. The mind boggles!
Why? Literally means ‘sleep room’. cf Schlafzimmer, chambre à coucher.
I know what it means. Use your imagination a little bit 
There’s a hardware shop in Macclesfield which has a lively window display of chains etc. Its name is S&M Supplies
I think the problem is if you speak another language relatively well the fact that a word in that language vaguely resembles something that might possibly be construed as risqué in say, English, rather passes you by.
Came across a question - is there an English word, a single word, for ‘the day after tomorrow’ ? Apparently there isn’t, but there is one in German - ‘Übermorgen’!
Coming back to my original word ‘Backpfeifengesicht’ which means ‘A face in need of a fist’ I would give this one my top marks because it fits in so well with the way I feel about those French motorists who tailgate me and come so close that I can see their faces in the rear view mirror!
In my mind’s eye there have been many fists in faces!
As there is in French “surlendemain”. No such compound noun in English, though, to my knowledge.
EDIT : turns out I was wrong, there is indeed an “overmorrow”, recorded at least in the 16th century and still in use in parliamentary debate in 1925.
The mirror image of übermorgen is vorgestern, very satisfying.