Definition

1. Proper noun:
   • The United States federal executive department responsible for coordinating and supervising all agencies and functions of the government directly related to national security and the United States Armed Forces. It is a cabinet-level department, headed by the Secretary of Defense, and was established by the National Security Act of 1947.

Usage

• The term "Department of Defense" is used as a proper noun to refer specifically to this U.S. government entity. It is often abbreviated as "DoD" or "DOD".
• It is typically used in formal, political, military, and journalistic contexts.

Examples

• Proper noun:
  • The Secretary of the Department of Defense will testify before Congress tomorrow.
  • The Department of Defense released its annual budget report.
  • He served as a civilian employee for the Department of Defense for twenty years.

Advanced Usage

• "The Pentagon": This term is often used as a metonym for the Department of Defense, as it is the name of the building that serves as its headquarters.
  • The decision was made at the Pentagon. (This implies the decision was made by the leadership of the Department of Defense.)

Variants and Related Words

• DoD / DOD: The standard abbreviation for the Department of Defense.
  • DoD officials declined to comment.
• Secretary of Defense: The title of the civilian head of the Department of Defense.
• Defense Department: A common alternative phrasing, though "Department of Defense" is the official name.

Synonyms

• The Pentagon (when used as a metonym for the department's leadership and functions).
• U.S. Defense Department.

Notes

• The term "department of defense" (not capitalized) could theoretically refer to a similar ministry in other countries, but in English and especially in American contexts, "the Department of Defense" (capitalized) almost exclusively refers to the United States institution. Other countries often use terms like "Ministry of Defence" (e.g., in the UK, Canada).

Noun

1. the federal department responsible for safeguarding national security of the United States; created in 1947