A word in one language may be quite innocent but in another language it has an offensive meaning or may even be a taboo word. It is not difficult to find such words in English and Swedish. They are usually about sexuality or body functions. Fart is such a word.

Fart in English is what you do when you let out gas through your anus or the sound of that action. A nicer way to express this is to say break wind, which is what Old English feortan meant. The corresponding Swedish verb is fisa or prutta.

Fart in Swedish comes from Low German faren, to travel.

Traffic sign with the image of a lorry and the Swedish word Infart (Entrance).
One type of fart

In Swedish, fart means speed, velocity, or movement. Not surprisingly, traffic signs including the word are popular objects for English-speaking tourists taking photos. Infart means entrance and utfart exit from property premises.  Farthållare is Swedish for cruise control, fartkamera is speed camera, and maxfart is top speed. If you are fartblind, speed blind, you don’t realize that you are driving too fast—you have got used to the high speed. Then you may be considered a fartdåre, a speed maniac or a fartsyndare, literally ‘a speed sinner’, a speeder.

Traffic sign with 'walking pace' in Swedish.
Walking pace

Elevators in Denmark often have a sign saying I fart meaning under way. An anecdote says that, during a visit by Queen Elizabeth II, somebody realized just in time what the sign meant in English, and it was rapidly covered up.

Traffic sign showing a snail and with the text 'at a snail's pace' in Swedish.
At a snail’s pace

Fart is a typical example of a false friend. False friends are words in two languages that look and/or sound similar but whose meanings are completely or partially different. See some more English–Swedish false friends here and examples from a few languages here. You can read about more than 400 English–Swedish false friends in my book (copyeditor.se/books).