This is the 840th most frequent Hungarian word.
szegedi
"Of or relating to Szeged," a city in Hungary.
Here "szegedi" acts as an adjective derived from "Szeged," describing the type or style of fish soup associated with or originating from the city.
Szegedi halászlé az egyik leghíresebb magyar étel.
Fish soup from Szeged is one of the most famous Hungarian dishes.
In this sentence, "szegedi" serves as an adjective modifying "múzeumba" (museum), referring to the museum that is located in the city of Szeged.
A híres szegedi múzeumba látogattunk el tegnap.
We visited the famous museum in Szeged yesterday.
Here "szegediből" is a declined form of "szegedi" that includes a suffix indicating origin or source, showing the relation to Szeged.