defensive measures designed to destroy attacking enemy aircraft or missiles or to nullify their effectiveness
(military) military action or resources protecting a country against potential enemies
the justification for some act or belief
(sports) the team that is trying to prevent the other team from scoring
the federal department responsible for safeguarding national security of the United States; created in 1947
a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of
a slight wind (usually refreshing)
