Greek scholar and rhetorician. The emperor Commodus appointed him to a chair of rhetoric in Athens. He wrote an Onomasticon, a Greek thesaurus of terms. The 10-volume work, which has survived incomplete, contains rhetorical material and technical terms relating to a wide variety of subjects, as well as citations from literature. It is especially interesting in its discussion of music and the theatre, as well as its treatment of law and the vocabulary of the law courts. The grammarian Pamphilus of Alexandria (1st century AD) was a significant lexicographical source.