secret agent◼◼◼(member of an intelligence agency whose identity or affiliation is kept confidential) noun [UK: ˈsiː.krɪt ˈeɪ.dʒənt] [US: ˈsiː.krət ˈeɪ.dʒənt]
agent secretnom
undercover◼◼◻(A person who works undercover) noun [UK: ˌʌn.dəˈk.ʌ.və(r)] [US: ˌʌn.dərˈk.ə.vər]