Here's why:
* Multiple Elvish Languages: Tolkien's works feature several Elvish languages, each with its own vocabulary and grammar: Quenya, Sindarin, and others. A word for "griffin" in one language might not exist in another.
* Mythological Creatures: Griffins are creatures of myth and legend, not necessarily part of the Elvish world's natural fauna. Tolkien didn't explicitly create a term for them in any of his Elvish languages.
Possible Approaches:
* Descriptive Terms: You could use descriptive phrases based on the griffin's characteristics:
* Quenya: *Híril-luin* (lion-eagle)
* Sindarin: *Lân-gûg* (lion-bird)
* Creative Translation: You could invent a term based on the root words of "lion" and "eagle" in Elvish:
* Quenya: *Híril-éagor* (lion-eagle, combining the roots of "hîril" and "éagor")
* Sindarin: *Lân-gael* (lion-bird, combining the roots of "lân" and "gael")
Ultimately, the choice depends on the context of your use and the specific Elvish language you're working with.