Tarquinius vs Tarquin the Proud

Tarquinius and Tarquin the Proud both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tarquinius	Yes	No	No	No
Tarquin the Proud	Yes	No	No	No

As nouns, Tarquinius and Tarquin the Proud are synonyms defined as:

Tarquinius and Tarquin the Proud: according to legend, the seventh and last Etruscan king of Rome who was expelled for his cruelty (reigned from 534 to 510 BC)

Other synonyms of Tarquinius include Lucius Tarquinius Superbus, Tarquin, Tarquinius Superbus.

Tarquinius (noun)	Tarquin the Proud (noun)
according to legend, the seventh and last Etruscan king of Rome who was expelled for his cruelty (reigned from 534 to 510 BC)	according to legend, the seventh and last Etruscan king of Rome who was expelled for his cruelty (reigned from 534 to 510 BC)