The story
From the tribe's self-designation, most likely Illyrian. Doublet of Livornian.
Etymology from Wiktionary, CC BY-SA 4.0.
Liburnian
Today it means: Any member of an ancient Illyrian tribe inhabiting the district called Liburnia, a coastal region of the northeastern Adriatic between the rivers Arsia (Raša) and Titius (Krka) in what is now Croatia. Full definition →