Alphabtus
Alphabtus is a fictional language created by J.R.R. Tolkien for his Middle-earth legendarium. It is a constructed language, or conlang, designed to serve as a secret language spoken by the Elves of Middle-earth. The name "Alphabtus" is a combination of the Elvish words "alph" (fire) and "abtus" (hidden or secret), reflecting the nature of the language as a means of concealment.
The language is based on the Elvish tongue Quenya, but it is simplified and adapted for use
In Tolkien's works, Alphabtus is used by various Elven characters to communicate secretly with one another.
Despite its fictional nature, Alphabtus has gained a dedicated following among linguists and fans of Tolkien's