Several years before hobbits were a gleam in J. R. R. Tolkien’s eye, he was deeply involved in another massive literary undertaking: The Oxford English Dictionary. Tolkien worked on the OED staff from 1919 to 1920, concentrating primarily on words in the “W” section. (The image of the tweedy young scholar beavering away at his obscure assignments at the dawn of the Jazz Age calls to mind an Oxbridge version of Ball of Fire; only sans Barbara Stanwyck.)
According to Peter Gilliver of the OED, Tolkien was put on to certain words — like walnut, walrus, and wampum — particularly because of their difficult etymologies:
Other words, such as waistcoat, wake (noun), wan, and want, posed rather different challenges. Teasing out fine distinctions of meaning is a key part of a lexicographer’s job, as is the selection of words to convey precisely the connotations, as well as the simple meaning, of a word: Tolkien evidently took great pains over both. He relished the task of distinguishing the different garments denoted at different times by waistcoat (as he later grew to relish the garment itself) … His biggest challenge, however, must surely have been want, one of the commonest of all verbs, which eventually required nearly thirty separately defined senses and subsenses.
Many years later, an editor at the OED who had been a student of Tolkien’s wrote asking for his opinion on the definition of a new word gaining popularity: hobbit. Tolkien happily obliged. Mithril and orc are now also ensconced in the dictionary as well.