After having used Babelfish for all this time, I finally checked out online dictionary Dict.cn, which Jay Dautcher told me about a year or two ago. It's really good, especially if you read Chinese, because it provides you with the word you're looking for in various sentences.  You can get a sense of how the word works.  Another nice touch is that it gives you the pinyin, with tones. For instance, I was looking for different definitions of the character 偶, and this is what it gave me:

Jay also recommends Wordmind.com, which in a search for the same character turned up dozens and dozens of recommendations, definitions in Chinese and English, and sentences.  Harder, perhaps, to find what you're looking for, but definitely broader and deeper.