Defend

Antonyms of defend:
assail, attack, prosecute, bombard, storm, beset, besiege, overrun, capitulate, cave, submit, yield, assault, abandon, abjure, forsake, recant, retract, take back, withdraw, reverse, switch, controvert, disprove, rebut, refute.
Examples of usage:
  1. It is my duty to tell you this in order that every man may be prepared to defend himself and his family.
    "The White Squaw", Mayne Reid.
  2. Do you defend her?
    "Roderick Hudson", Henry James.
  3. But since you're here, Draw and defend yourself.
    "Black Beetles in Amber", Ambrose Bierce.