завуальований, таємний, секретний; прихований, не очевидний
clandestine operation; covert operation
covert action
covert activities
covert amphibious entry
covert attack
covert delivery
covert forces
covert intelligence
covert operation
covert propaganda
covert warfare
covert way
carry out covert action
covert activity
covert influence operation
covert intelligence officer identities
covert intelligence work
covert ops
information from covert sources