Admittedly it is quite an odd word. And also probably not entirely true. Not all wifebeaters wear such shirts, and not everyone who wears such a shirt is a wifebeater! In German it is simply called "Unterhemd" (undershirt, as you wear it under the clothes).
Thinking further about it, I remembered that there is a special kind of collar on a shirt that is called "Vatermörder" in German. Father murderer. Not really better!
Do you have any other examples?