Out of curiosity what do you think of David Day’s A Dictonary of Tolkien? I imagine yours is more comprehensive?
Honestly I am unfamiliar with it. Is it posted on line or published?
I worked about five years on mine, took time off of FR. When the Tolkien estate refused to allow it to be published I posted it on line and moved on. At that time it was the only comprehensive full Tolkien dictionary in the world.
I am an amateur linguist and on some terms with no Tolkien guidance - like the horse's name Asfaloth - I used eclectic interpretive methods, thinking of Tokien's own thinking when he used those phonetic elements. When further Tolkien notes were found and published I pointed out to the official linguists that many of my interpretations were correct.
Their response: I was just lucky.
I decided to move on.
I dont have that one but I have a number of others including The Complete Guide to Middle Earth by Robert Foster