Dictionary app help

Since nobody has replied to you yet, i gave it a gander. Google is your friend.
Dictionary link help

 

This is all I could find for you. (There's not a lot out there, or maybe I was just searching the wrong area of the internet).

http://lipflip.org/articles/dictcc-dictionary-plugin

 

Ultralingua, linked to by ObuckiO, does seem to have offline german-english dictionaries
http://www.ultralingua.com/products

Another series, which can be purchased either from the web or the Mac App store, is this one
http://www.penreader.com/mac-os-software/SlovoEd.html

There may be more, I just did a quick search, and I don't know if they are any good.

If you try some translation dictionaries please update this thread with which ones you liked and which ones you didn't like.

 

I use this: http://www.macupdate.com/app/mac/27086/beolingus-german-english-dictionary-plugin

Put it in your dictionaries folder. Works a treat on Lion.