Coastal city on Taprobane (modern Sri Lanka); Ptol. 7,4,7. It seems obvious to identify it with the Middle Indian Nāgadīpa ‘Island of serpents’, but no city with this name is known.
Karttunen, Klaus (Helsinki),
“Nagadiba”, in:
Brill’s New Pauly, Antiquity volumes edited by: Hubert Cancik and , Helmuth Schneider, English Edition by: Christine F. Salazar, Classical Tradition volumes edited by: Manfred Landfester, English Edition by: Francis G. Gentry.
Consulted online on 10 June 2023 <http://dx.doi.org/10.1163/1574-9347_bnp_e816300>