агент нелегальної розвідки; розвідник-нелегал (про розвідку / термін спецслужб)
undercover operation
work undercover
undercover apparatus
undercover intelligence asset
undercover international apparatus
undercover movement
undercover work
agent / agent network / agents
CW agent (chemical warfare agent)
obscurant agent (vision-restricting agent)
damage agent / damaging agent
agent vapor
anti-plant agent
automatic chemical agent alarm
biological agent
blister agent/ gas
blood agent
chemical agent detector
chemical agent detector kit
chemical agent detector paper
chemical agent dissemination
chemical warfare agent
choking agent / gas
corrosive agent
deep-cover agent
defoliating agent
depolymerizing agent
germ warfare agent
harassing agent
ignition agent
incapacitating agent
incendiary agent