What is "goldogrin"

Goldogrin is a constructed language devised by J. R. R. Tolkien and used in his secondary world, often called Middle-earth. Goldogrin was spoken by the Second Clan of Elves, called Goldorim in that language, Gnomes in English (whence Gnomish for their language). In The Book of Lost Tales the second clan of Elves was also known in Elfin as the Noldoli and their language was called Noldorin.