What is the meaning of shoot down?

verb

• Move quickly and violently.
  • usage: "The car tore down the street"; "He came charging into my office"
  • synonyms: tear, shoot, charge, buck
• Shoot at and force to come down.
  • usage: "the enemy landed several of our aircraft"
  • synonyms: down, land
• Thwart the passage of.
  • usage: "kill a motion"; "he shot down the student's proposal"
  • synonyms: kill, defeat, vote down, vote out