English to Mandarin dictionary with idioms, slang and jargon

A couple of months ago, a Chinese student referred me to an online dictionary that translated not just individual English words, but English phrases, idioms, jargon, slang, etc. into Mandarin. I remember looking at it and agreeing that it was excellent, but now that I want to find it again I can't remember what the url was and I've been Googling madly for 20 minutes now without finding it! This, I thought to myself, is a case for those linguaphiles. Anyone know what it might be, or have a recommendation for a good online dictionary which does this?