| Noun | 1. | DIA - an intelligence agency of the United States in the Department of Defense; is responsible for providing intelligence in support of military planning and operations and weapons acquisition Defense Department, Department of Defense, DoD, United States Department of Defense, Defense - the federal department responsible for safeguarding national security of the United States; created in 1947 armed forces, armed services, military, military machine, war machine - the military forces of a nation; "their military is the largest in the region"; "the military machine is the same one we faced in 1991 but now it is weaker" military intelligence, military intelligence agency - an agency of the armed forces that obtains and analyzes and uses information of strategic or tactical military value United States intelligence agency - an intelligence service in the United States IC, Intelligence Community, National Intelligence Community, United States Intelligence Community - a group of government agencies and organizations that carry out intelligence activities for the United States government; headed by the Director of Central Intelligence |