diarthrosis vs synovial joint

diarthrosis and synovial joint both are nouns.

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

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

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

Other synonyms of diarthrosis include articulatio synovialis.

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