Constructed Language: Both in and out of universe, Eldraeic is a constructed language.
In-universe, it’s a constructed language designed as an interlingua for the Empire by the Conclave of Linguistics and Ontology, with additional requirements for regularity, unambiguity, cultural neutrality where matters other than The Fundamentals are concerned and linguistic imperialism where they are, maximal flexibility, designed to allow the greatest scope for creativity, and simultaneously to promote logical reasoning and precision, and designed to be expressively isomorphic in multiple forms. This heady list of requirements was then tackled by a group of linguists, philosophers, logicians and mathematicians, whose work and arguments produced the language we know today.
Out of universe, it’s also a constructed language, albeit an unfinished one (and given its claims to universality, a perpetually unfinished one – I don’t have the nose to produce the olfactory-description features it inherited from the dar-bandal, for example, never mind some of the real esoterica it’s acquired from various other Starfish Languages). Nor, while I can describe in great detail its 36-character alphabet — well, 3.5 alphabets (for pen, brush, and chisel, the additional half being a variant on the brush alphabet for scratching with claws) and dozen or so phonologies (for different speech apparati, including things like radio and chromatophore matrix), do I actually have them all terribly well defined. Nonetheless, it’s constructed enough that it is possible to say things in it, and even – having participated in a conlang relay or two – for other people to understand what was said.
Type-wise, it’s somewhere between “complete original” and “foreign conversion” – originally, I started using Loglan/lojban as a base, but it’s grown up to be a very different language (it uses case tags than place structures, for one thing, along with many other affixes, and handles a lot of shared features differently, and comes with a lot of different or at least differently implemented features). And it’s nothing at all like English, certainly!