The Collaborative International Dictionary
Defiantness
Defiant \De*fi"ant\, a. [Cf. F. d['e]fiant, p. pr. of d['e]fier. See Defy.] Full of defiance; bold; insolent; as, a defiant spirit or act.
In attitude stern and defiant.
--Longfellow.
-- De*fi"ant*ly, adv. -- De*fi"ant*ness, n.
Wiktionary
defiantness
n. The state or quality of being defiant.