yuge,"steam".
Accompanying with students, I took a trip to a hot spring ammusement park. It gave me a few very relaxed moment. Watching beatiful steam raising from the pool, this term natually came to my mouth. However, when I told it to my students, I realized that "steam" was my only choice in English. 湯気 is steam, but there are also other wrods in Japanese mean "steam", including スチーム and 水蒸気. Thus I experienced a moment of frustration for not being able to find a better word to describe the scenery in front o f me.
I understand that this certainly does not become an evidance to argue that Japanese has richer vocabulary, although I can imagine that many may want to jump into that conclusion without a second thought.