we found the word "cratylic". What is the origin of this word?

I couldn't find it in any dictionaries I looked it up in (OED, Onelook, etc.). I assume it comes from the Greek proper name, Cratylus. He is a character in one of Plato's Socratic dialogs of the same name. He champions the idea that language is natural (physis) and not conventional (nomos). So rather than an arbitrary association of objects and words, the association between an object and its name is determined.

Ceci n'est pas un seing.