armilla vs armillary sphere

armilla and armillary sphere both are nouns.

Word	Noun	Adjective	Verb	Adverb
armilla	Yes	No	No	No
armillary sphere	Yes	No	No	No

As nouns, armilla and armillary sphere are synonyms defined as:

armilla and armillary sphere: a celestial globe consisting of metal hoops; used by early astronomers to determine the positions of stars

armilla (noun)	armillary sphere (noun)
(archeology) a bracelet worn around the wrist or arm	a celestial globe consisting of metal hoops; used by early astronomers to determine the positions of stars
a celestial globe consisting of metal hoops; used by early astronomers to determine the positions of stars