Every so often, I'll learn about a word in another language that means something very specific and think, "That would be convenient if we had a word for that in English, too!"
Here is a small sampling:
1. Chon shu (Chinese): to be nauseous from the heat
2. Fedderchei (Dutch): feeling hesitant to write people letters
3a. Tios (Spanish): aunts & uncles
3b. Sobrinos (Spanish): nieces & nephews
That last one really irks me, actually. Most languages have a way to abbreviate "aunts and uncles" and "nieces and nephews" (I just picked Spanish for the example), but English-speakers always have to write it out the long way. We have "siblings", "parents", "children", etc, but that part of the family can't be easily summarized. Why?
In these days of twitter and texting, being concise is important! Maybe I'll start using these words and eventually they'll become English, too. :)