contumacy vs rebelliousness

contumacy and rebelliousness both are nouns.

Word	Noun	Adjective	Verb	Adverb
contumacy	Yes	No	No	No
rebelliousness	Yes	No	No	No

As nouns, rebelliousness is a hypernym of contumacy; that is, rebelliousness is a word with a broader meaning than contumacy:

contumacy: obstinate rebelliousness and insubordination; resistance to authority
rebelliousness: an insubordinate act

Other hypernyms of contumacy include insubordination.

contumacy (noun)	rebelliousness (noun)
willful refusal to appear before a court or comply with a court order; can result in a finding of contempt of court	an insubordinate act
obstinate rebelliousness and insubordination; resistance to authority	intentionally contemptuous behavior or attitude