Antonius vs Antony

Antonius and Antony both are nouns.

Word	Noun	Adjective	Verb	Adverb
Antonius	Yes	No	No	No
Antony	Yes	No	No	No

As nouns, Antonius and Antony are synonyms defined as:

Antonius and Antony: Roman general under Julius Caesar in the Gallic wars; repudiated his wife for the Egyptian queen Cleopatra; they were defeated by Octavian at Actium (83-30 BC)

Other synonyms of Antonius include Anthony, Marcus Antonius, Mark Anthony, Mark Antony.

Antonius (noun)	Antony (noun)
Roman general under Julius Caesar in the Gallic wars; repudiated his wife for the Egyptian queen Cleopatra; they were defeated by Octavian at Actium (83-30 BC)	Roman general under Julius Caesar in the Gallic wars; repudiated his wife for the Egyptian queen Cleopatra; they were defeated by Octavian at Actium (83-30 BC)