U. S. Air Force vs Defense

U. S. Air Force and Defense both are nouns.

Word	Noun	Adjective	Verb	Adverb
U. S. Air Force	Yes	No	No	No
Defense	Yes	No	No	No

U. S. Air Force (noun)	Defense (noun)
the airforce of the United States of America; the agency that defends the United States through control and exploitation of air and space	the federal department responsible for safeguarding national security of the United States; created in 1947