intelligence activities concerned with identifying and counteracting the threat to security posed by hostile intelligence organizations or by individuals engaged in espionage or sabotage or subversion or terrorism
inquire into; "the students had to research the history of the Second World War for their history project"; "He searched for information on his relatives on the web"; "Scientists are exploring the nature of consciousness"
attempt to find out in a systematically and scientific manner; "The student researched the history of that word"