ankle vs gliding joint

ankle and gliding joint both are nouns.

Word	Noun	Adjective	Verb	Adverb
ankle	Yes	No	No	No
gliding joint	Yes	No	No	No

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

ankle: a gliding joint between the distal ends of the tibia and fibula and the proximal end of the talus
gliding joint: a freely moving joint in which the articulations allow only gliding motions

Other hypernyms of ankle include articulatio plana.

ankle (noun)	gliding joint (noun)
a gliding joint between the distal ends of the tibia and fibula and the proximal end of the talus	a freely moving joint in which the articulations allow only gliding motions