Salonica vs Thessalonica

Salonica and Thessalonica both are nouns.

Word	Noun	Adjective	Verb	Adverb
Salonica	Yes	No	No	No
Thessalonica	Yes	No	No	No

As nouns, Salonica and Thessalonica are synonyms defined as:

Salonica and Thessalonica: a port city in northeastern Greece on an inlet of the Aegean Sea; second largest city of Greece

Other synonyms of Salonica include Salonika, Thessaloniki.

Salonica (noun)	Thessalonica (noun)
a port city in northeastern Greece on an inlet of the Aegean Sea; second largest city of Greece	a port city in northeastern Greece on an inlet of the Aegean Sea; second largest city of Greece