a belief that can guide behavior; "the architect has a theory that more is less"; "they killed him on the theory that dead men tell no tales"
a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses"; "true in fact and theory"
a steady advance; "the march of science"; "the march of time"
the act of marching; walking with regular steps (especially in a procession of some kind); "it was a long march"; "we heard the sound of marching"
a procession of people walking together; "the march went up Fifth Avenue"
the month following February and preceding April
walk fast, with regular or measured steps; walk with a stride; "He marched into the classroom and announced the exam"; "The soldiers marched across the border"
march in a procession; "They processed into the dining room"
force to march; "The Japanese marched their prisoners through Manchuria"
cause to march or go at a marching pace; "They marched the mules into the desert"
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