knee joint vs ginglymoid joint

knee joint and ginglymoid joint both are nouns.

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

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

knee joint: hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella
ginglymoid joint: a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane

Other hypernyms of knee joint include ginglymus, hinge joint.

knee joint (noun)	ginglymoid joint (noun)
hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella	a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane