Sindarin is the fictional language J.R.R. Tolkien created with strong Welsh-inspired influences.
In Tolkien’s mythology, Sindarin is a language of the Sindar, or Grey Elves, and it became the everyday Elvish language of many Elves in Middle-earth during the later Ages. Tolkien designed its sound patterns and historical development as part of a family of related Elvish languages rather than as a collection of isolated vocabulary.
Quenya, another major Elvish language, was influenced especially by Finnish and Latin-like features and served as a more formal or ancient language. Sindarin appears frequently in names such as Galadriel, Celeborn, and Minas Tirith. Tolkien’s linguistic work was unusually detailed: he developed sound changes, grammar, and fictional histories for his languages.