Overt, covert, or clandestine activity designed to obtain information relating to the national defense with intent or reason to believe that it will be used to the injury of the United States or to the advantage of a foreign nation. For espionage crimes see Chapter 37 of Title 18, United States Code.
ESPIONAGE AGAINST THE UNITED STATES
Meaning of ESPIONAGE AGAINST THE UNITED STATES in English
DOD English dictionary of military terms. Английский словарь военных терминов DOD. 2012