This is a rather simple trick I found by accident. If you open Dictionary in Applications you will see a variety of different dictionaries and there names. You can actually re-name these dictionaries. This is quite useful if you have installed a personal dictionary and you want to give it a more appropriate name. Changing the names is really simple.
To rename a dictionary, right click on it in the small bar in which you can select dictionaries and select Edit Label. You will be given a text box in which you can put a name. Type what ever you want, although I recommend you name is something useful. This is a neat little trick if you want to name a foreign dictionary to something in English or vice-versa.
You can revert it back to the original, by right clicking on the label again, and selecting “Revert To Original Label”. A simply way to change what you dictionaries are called.