Webster's Revised Unabridged Dictionary · 1913

defy

defy (de*fī") , transitive verb

[French défier, Old French deffier, desfier, Late Latin disfidare to disown faith or fidelity, to dissolve the bond of allegiance, as between the vassal and his lord; hence, to challenge, defy; from Latin dis- + fides faith. See Faith, and compare Diffident, Affiance.]

1.
To renounce or dissolve all bonds of affiance, faith, or obligation with; to reject, refuse, or renounce. [Obsolete]
I defy the surety and the bond. — Chaucer
For thee I have defied my constant mistress. — Beau. & Fl
2.
To provoke to combat or strife; to call out to combat; to challenge; to dare; to brave; to set at defiance; to treat with contempt; as, to defy an enemy; to defy the power of a magistrate; to defy the arguments of an opponent; to defy public opinion.
I once again Defy thee to the trial of mortal fight. — Milton
I defy the enemies of our constitution to show the contrary. — Burke

defy (de*fī") , noun

A challenge. [Obsolete] — Dryden