noun

• The action of defending or protecting from attack, danger, or injury.
• Anything employed to oppose attack(s).
• (team sports) A strategy and tactics employed to prevent the other team from scoring; contrasted with offense.
• (team sports) The portion of a team dedicated to preventing the other team from scoring; contrasted with offense.
• An argument in support or justification of something.
• (law, by extension) The case presented by the defendant in a legal proceeding.
• (law, by extension) The lawyer or team thereof who presents such a case.
• (government, military, euphemistic) Government policy or (infra)structure related to the military.
• (obsolete) A prohibition; a prohibitory ordinance.