Definition

1. Noun:
   • A defensive structure consisting of a barrier that can be employed for defense against attack: This refers to a physical fortification, obstacle, or position designed to stop or slow an enemy's advance.
   • Any organization whose responsibility it is to defend against something: This refers to a group or system established to protect against a specific threat or problem.

Usage and Examples

• Noun (Physical Barrier):

  • The castle's outer wall was its first line of defence.
  • The soldiers dug a trench as a new line of defence against the advancing troops.

• Noun (Protective Organization/System):

  • A strong immune system is the body's primary line of defence against infection.
  • The cybersecurity team is our first line of defence against data breaches.

Advanced Usage

• "First/second/third line of defence": This phrase is used to describe a sequence of protective measures, where the first is the initial barrier or responder.
  • Vaccination is considered the first line of defence against the virus, with hospital care being the last.

Variants and Related Words

• Line of defense: The American English spelling variant of 'line of defence'.
• Defence (Noun): The act or means of protecting against attack, danger, or loss.
• Defensive (Adjective): Intended for or used in defence.

Synonyms

• Bulwark: A defensive wall or something that provides protection.
• Barrier: A fence or other obstacle that prevents movement or access.
• Safeguard: A measure taken to protect someone or something.

Related Phrases

• Line of defense (Phrasal Noun): Functions identically to 'line of defence'.
  • The firewall is our most important line of defense for the network.

Related Idioms

• The first line of defence: An idiom emphasizing the primary or most immediate protective measure.
  • In public health, education and awareness are the first line of defence.

Noun

1. defensive structure consisting of a barrier that can be employed for defense against attack
2. any organization whose responsibility it is to defend against something
   • police are the major line of defense against crime