zygomatic arch vs arcus zygomaticus

zygomatic arch and arcus zygomaticus both are nouns.

Word	Noun	Adjective	Verb	Adverb
zygomatic arch	Yes	No	No	No
arcus zygomaticus	Yes	No	No	No

As nouns, zygomatic arch and arcus zygomaticus are synonyms defined as:

zygomatic arch and arcus zygomaticus: the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone

Other synonyms of zygomatic arch include zygoma.

zygomatic arch (noun)	arcus zygomaticus (noun)
the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone	the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone