synovial joint vs diarthrosis

synovial joint and diarthrosis both are nouns.

Word	Noun	Adjective	Verb	Adverb
synovial joint	Yes	No	No	No
diarthrosis	Yes	No	No	No

As nouns, synovial joint and diarthrosis are synonyms defined as:

synovial joint and diarthrosis: a joint so articulated as to move freely

Other synonyms of synovial joint include articulatio synovialis.

synovial joint (noun)	diarthrosis (noun)
a joint so articulated as to move freely	a joint so articulated as to move freely