ginglymoid joint vs diarthrosis

ginglymoid joint and diarthrosis both are nouns.

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

As nouns, diarthrosis is a hypernym of ginglymoid joint; that is, diarthrosis is a word with a broader meaning than ginglymoid joint:

ginglymoid joint: a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane
diarthrosis: a joint so articulated as to move freely

Other hypernyms of ginglymoid joint include articulatio synovialis, synovial joint.

ginglymoid joint (noun)	diarthrosis (noun)
a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane	a joint so articulated as to move freely