Dragon, a fabulous monster, being a hideous impersonation of some form of deadly evil, which only preternatural heroic strength and courage can subdue, and on the subdual and slaying of which depends the achievement of some conquest of vital moment to the human race or some members of it; is represented in mediæval art as a large, lizard-like animal, with the claws of a lion, the wings of an eagle, and the tail of a serpent, with open jaws ready and eager to devour, which some knight high-mounted thrusts at to pierce to death with a spear; in the Greek mythology it is represented with eyes ever on the watch, in symbol of the evil that waylays us to kill us if we don't kill it, as in guarding the “Apples of the Hesperides” and the “Golden Fleece,” because these are prizes that fall only to those who are as watchful of him as he is of them; and it is consecrated to Minerva to signify that true wisdom, as sensible of the ever-wakeful dragon, never goes to sleep, but is equally ever on the watch.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Draco * Dragonnades