False friends can be a pitfall for translators. What is meant is pairs of words in two languages which sound similar but have different meanings. The words can either have a common origin, but have developed in different ways, or the similarity is purely coincidental. False friends are far more common in languages which are relatively closely related (e.g. German and Dutch) or in languages which have been in relatively close contact with each other (e.g. German and French) than in the case of languages not related to each other (e.g. German and Japanese). In the last example it is usually assumed automatically in the case of similar words that the similarity is a coincidence and so the problem does not arise in the first place.
Translation from the German Wikipedia online dictionary
An example of a false friend is the English term ‘billion’, which is not be translated into German by ‘Billion’ but by ‘Milliarde’.