Tingo, nakkele and other wonders lists a number of foreign words without English equivalents. I found the German examples more accessible than most:
The German propensity for compound words pays dividends. Kummerspeck is a German word which literally means grief bacon: it is the word that describes the excess weight gained from emotion-related overeating.A Putzfimmel is a mania for cleaning and Drachenfutter — literally translated as dragon fodder — are the peace offerings made by guilty husbands to their wives.
Or there’s die beleidigte Leberwurst spielen — to stick one’s lower lip out in a sulk (literally, to play the insulted liver sausage). Perhaps it’s a Backpfeifengesicht — a face that cries out for a fist in it.
(Hat tip to Geek Press, which also points to a more extensive list.)