peculiar language

A really distinguished style varies ordinary diction through the employment of unusual words. By unusual I mean strange words and metaphor and lengthened words and everything that goes beyond ordinary diction. But if someone should write exclusively in such forms the result would either be a riddle or a barbarism. A riddle will result if someone writes exclusively in metaphor; and a barabarism will result if there is an exclusive use of strange words. . . . It is therefore necessary to use a combination of all these forms. The employment of strange words and metaphor and ornamental words and the other forms of speech that have been mentioned will prevent the diction from being ordinary and mean; and the use of normal speech will keep the diction clear.

Aristotle, Poetics 1458a