J.R.R. Tolkien called his high-elven language Quenya. He developed it as part of his invented linguistic history for the Elves, drawing on Finnish as one important inspiration along with other languages.
Quenya is associated especially with the Eldar and with the Elves who lived in Valinor. In Tolkien’s fictional history, it became a formal and literary language, somewhat like a classical language preserved for ceremony, poetry, and tradition. Tolkien created vocabulary, grammar, sound patterns, and historical forms for it rather than treating it as a collection of decorative names.
Sindarin is a different Elvish language and is more commonly used by many Elves in Middle-earth during The Lord of the Rings. Khuzdul is the language of the Dwarves, while the Black Speech was created for Mordor. These distinctions make “Elvish” too broad when Quenya is the intended answer.