The Tolkien-created language whose name means “high-elven” is Quenya.
Quenya is one of Tolkien’s most developed Elvish languages. He based aspects of its sound and structure on languages including Finnish, while also giving it its own vocabulary, grammar, history, and internal development. In Tolkien’s mythology, Quenya is associated especially with the High Elves and the ancient realms of Valinor.
By the time of The Lord of the Rings, Quenya functions largely as a formal, literary, or ceremonial language among many Elves of Middle-earth. Sindarin, another major Elvish language, is more commonly spoken by Elves in much of the story. Tolkien’s linguistic construction was central to his world-building rather than an afterthought.
Readers sometimes use “Elvish” as though it names one language, but Tolkien created several Elvish tongues and dialects. Quenya and Sindarin are the two most prominent and extensively developed examples in his published fiction.