Source : Webster's Revised Unabridged Dictionary (1913)

Rebellious \Re*bel"lious\, a.
   Engaged in rebellion; disposed to rebel; of the nature of
   rebels or of rebellion; resisting government or lawful
   authority by force. ``Thy rebellious crew.'' ``Proud
   rebellious arms.'' --Milton. -- {Re*bel"lious*ly}, adv. --
   {Re*bel"lious*ness}, n.

Source : WordNet®

rebelliousness
     n 1: intentionally contemptuous behavior or attitude [syn: {defiance}]
     2: an insubordinate act [syn: {insubordination}]