Existent vs. Extant
What’s the difference between existent and extant? It might be more appropriate to ask, what’s the difference between exists and “is extant”? Existent usually seems awkward to me; exists or “to exist” often seems more suitable. (Even a comparative sentence such as “Unicorns are just as existent as umbrellas” seems odd — and not just because of the subject matter; though the meaning is not exactly the same, I would instead write, “Unicorns are just as likely to exist as umbrellas.”)
The root word for both terms is exist, from the Latin term existere, which means “to emerge” or “to stand forth” (hence the ex- element, which means “out of” or “from”), as well as “appear” or “be.”
The adjective existent derives from the noun existence, which stems from the Latin term existentia, itself coming from existentem, which means — you guessed it, “existent.” (The second syllable, from sistere, which means “cause to stand,” is also found in assist and subsist and their variants.)
Synonyms include inherent (verb form inhere), from the Latin term inhaerere, “to stick in or to,” and the aforementioned subsist, which has a connotation of minimal survival.
Several other words that include the root exist are coexist (“exist together” or “live together peacefully”) and preexist (“to exist beforehand”), as well as existential, which refers to a philosophy centering on the absence of certainty about morality, which has overshadowed the generic meanings of “grounded in existence” or “relating to existence.” And then there’s the unfortunately obsolete existimation, a synonym for esteem or estimation.
So, what about extant? Its Latin origin is extare, which means “stand out, be visible, exist,” but it has acquired a slightly different connotation — a more extended one — than existence: It means “in existence,” even “still in existence.” Thus, to say that something exists and to say that it is extant are two distinct statements.
What this means is that extant is appropriate for describing something that still remains or survives, though it is reasonable to assume that something might not do so. It’s employed usually in references to artifacts and documents, or to species and other categories of biological classification. Something that exists, by contrast, merely is.