Defense (noun)

1. The act of defending or the state of being defended.
2. The measures taken to protect something.
3. The military action or resources protecting a country against potential enemies.
4. The justification or explanation of a position or action.
5. The legal protection of a person or property against prosecution or attack.

Origin:

Middle english, from old french, from latin defensa, from feminine of defensus, past participle of defendere.

Examples:

1. The castle was built for defense against invaders.
2. She put up a defense against the accusations.
3. The country's defense budget was increased.
4. He made a defense for his position.
5. The lawyer provided a strong defense for the client.