There are plenty of Chinese idioms about loong, and here are some proper translations. Cheng long kuai xu (乘龙快婿) whose literal meaning is that a well-content son-in-law is just like riding a loong bringing happiness, so its proper translation should be “a son-in-law of high rank”. And the phrase che shui ma long (车水马龙) is to describe the blockage and crowding of traffic, accordingly its proper translation ought to be “heavy traffic”.
In modern Chinese, loong in some phrases has lost its original meaning, and got meanings of trope. Such as, the phrase shui long tou, which looks like loong. The phrase yi tiao long is not a real loong, but series of good methods or ways.
Huang Ji, who is the professor in East China Normal University, brought forward that the best translation of long is loong. Besides Huang ji, Taiwan scholar Meng Tianxiang also pointed out the same opinion. I also agree with it. 从对龙的阐释看中西文化差异(3):http://www.youerw.com/yingyu/lunwen_6950.html