knock-knee vs disability

knock-knee and disability both are nouns.

Word	Noun	Adjective	Verb	Adverb
knock-knee	Yes	No	No	No
disability	Yes	No	No	No

As nouns, disability is a hypernym of knock-knee; that is, disability is a word with a broader meaning than knock-knee:

knock-knee: an inward slant of the thigh
disability: the condition of being unable to perform as a consequence of physical or mental unfitness

Other hypernyms of knock-knee include disablement, handicap, impairment.

knock-knee (noun)	disability (noun)
an inward slant of the thigh	the condition of being unable to perform as a consequence of physical or mental unfitness