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
call to remembrance; keep alive the memory of someone or something, as in a ceremony; "We remembered the 50th anniversary of the liberation of Auschwitz"; "Remember the dead of the First World War"
be or provide a memorial to a person or an event; "This sculpture commemorates the victims of the concentration camps"; "We memorialized the Dead"
mark by some ceremony or observation; "We marked the anniversary of his death"
the discipline that studies the principles of transmiting information and the methods by which it is delivered (as print or radio or television etc.); "communications is his major field of study"