1Any of various secretaries, ministers, or officials of the State, or of a state; (now especially) (frequently with for, of) an official in charge of a particular state department.
2Also with capital initials. The chief government official responsible for the foreign affairs of a State; specifically (with reference to the United States) = "Secretary of State".
Mid 17th century; earliest use found in Rump righteously handled in New Ballad. From state + secretary.