from The Century Dictionary.
- Pertaining to the Roman emperor Nero (54–68
a. d.), or to his reign; characteristic of or resembling Nero; grossly cruel and tyrannical.
Sorry, no etymologies found.
Moreover, there is nothing neronian about the protagonists '(both the narrator and his brother are botanist-philosophers) devotion to intellectual pursuits.
An Exchange on Ernst Jünger Barr, Hilary 1993