Lord of the Rings Online for game design, class balance, or the like, then you might not be terribly concerned with the nuances of the functional languages that Tolkien developed for the original books. But if you really care about giving your Dwarf weapons with more resonant names than "Foe-hewer," you probably would be interested in A Casual Stroll to Mordor's latest post about expanding the rather anemic Dwarven tongue.
Using the Hebrew linguistic structure as a base, the article goes into depth about making logical alterations to existing words, and from there, creating new words that fit into the established structure. It's a fascinating post for Lord of the Rings Online players as well as anyone who likes developed in-game lore, as it shows just how much can be done within the given setting. And if you're a player in LotRO who'd like to use some more Dwarven names, there are interesting charts available along with some example names.