contumacious (adj) – contemptuous of authority; willfully disobedient
BREAKDOWN: CON- (with) + TUM- (to be proud) + -ACIOUS (inclined to)
— contumacy is contemptuous or willful disobedience, resistance to authority
This word is built on the root TUM-, which means to swell or to be proud.
Common TUM- words include tomb and tumor.
More esoteric TUM- words include contumely, tumefacient, and tumulous.