Termium Plus, the Canadian database (French, English and Spanish) is now free online.
I believe it is useful for the English alone (the default setting on the site is to look up French terms). It has such a full set of definitions and examples that it should help translators between German and English too. It has been (rightly) expensive on CD so I have never become familiar with it.
(I’m trying to read Infinite Jest, so when I see a Canadian site I keep thinking about terrorists in wheelchairs, I’m afraid).
Here’s one description to make up for my ignorance (it refers to charges, which have now gone).