I did some additional research into the autotranslate function and discovered that you can add items to it. You can NOT add phrases, words, etc - just items. This just works for normal items. Doesn't work for key items, all Key items are in translate by default SE. I've added links below that should help. I did Google the subject to make sure I covered the topic and discovered that the year I quoted in my original answer, 2007, the year I started playing - was the year they enabled the feature where you could add to autotranslate, but they later locked down WHAT you csould add to it. Hope this helps!! Main command for adding is below - links below that. Skyfiredancer (talk) 13:59, October 30, 2015 (UTC)
This list of items changes constantly. With a maximum capacity of 200, it is populated as you view items in your inventory, equipment slots, bazaars, and the auction house, and when you see an auto-translated item name in chat. The items appear in alphabetical order, but the game maintains some kind of internal queue (FIFO) structure to replace the oldest items with new ones when it is full. Items currently in your inventory will always stay in this list. If you have already used the translation of an Item in the list, it will then allow you to use the auto-complete feature on that item if you wish to type it again for translation.
Use the /translate command to manually add an item to your dictionary.
You must use the abbreviated form of the item name exactly as it appears in inventory lists.
You may first need to press the SPACE and then TAB keys before the item name is added to the dictionary.