Definition of "incunable"

Nerciat rubbed shoulders with D.H. Lawrence, the Large Paper set of de Sade (Illustrated by Austin Osman Spare) jostled an incunable Hermes Trismegistus, and ten different editions of L'Histoire d'O were piquant bedfellows to De la Bodin's Démonomanie des Sorciers.

1976, Kyril Bonfiglioli, Something Nasty in the Woodshed, Penguin, published 2001, page 435