Thessaly vs Thessalia

Thessaly and Thessalia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Thessaly	Yes	No	No	No
Thessalia	Yes	No	No	No

As nouns, Thessaly and Thessalia are synonyms defined as:

Thessaly and Thessalia: a fertile plain on the Aegean Sea in east central Greece; Thessaly was a former region of ancient Greece

Thessaly (noun)	Thessalia (noun)
a fertile plain on the Aegean Sea in east central Greece; Thessaly was a former region of ancient Greece	a fertile plain on the Aegean Sea in east central Greece; Thessaly was a former region of ancient Greece