What is the meaning of defend?

verb

• Argue or speak in defense of.
  • usage: "She supported the motion to strike"
  • synonyms: support, fend for
• Be on the defensive; act against an attack.
• Protect against a challenge or attack.
  • usage: "Hold that position behind the trees"; "Hold the bridge against the enemy's attacks"
  • synonyms: guard, hold
• Fight against or resist strongly.
  • usage: "The senator said he would oppose the bill"; "Don't fight it"
  • synonyms: fight, oppose, fight back, fight down
• Protect or fight for as a champion.
  • synonyms: champion
• Be the defense counsel for someone in a trial.
  • usage: "Ms. Smith will represent the defendant"
  • synonyms: represent
• State or assert.
  • usage: "He maintained his innocence"
  • synonyms: maintain