Actually a lot of his 'created' words are more 'lifted' straight from the textbooks he taught out of. Orc is an Anglo Saxon
word for 'demon', Ent was the same - 'giant'. Arwen
and Arwenna are the feminine forms of Arwyn which meant 'fair, fine'. Even in Legolas
- the Welsh for 'green' is 'glas'. Tolkien's genius was in pulling from his rich knowledge of all these ancient languages and legends and seamlessly weaving them together like that. I've never actually managed to read through the books all the way (pathetic, I know, but I have the attention span of a tsetse fly) but the appendixes are well thumbed!
You might also like Awel/Awela, Welsh, means 'breeze' and if you're into subtle but cool the Welsh for 'leaf' is Dalen.Devon