n a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite
n the capacitance of a capacitor that has an equal and opposite charge of 1 coulomb on each plate and a voltage difference of 1 volt between the plates
n 32nd President of the United States; elected four times; instituted New Deal to counter the Great Depression and led country during World War II (1882-1945)
n a secret federal court created in 1978 by the Foreign Intelligence Surveillance Act; responsible for authorizing wiretaps and other forms of electronic surveillance and for authorizing searches of suspected spies and terrorists by the Department of Justice or United States intelligence agencies
n the highest region of the ionosphere (from 90 to 600 miles up) which contains the highest concentration of free electrons and is most useful for long-range radio transmission