un·der·cov·er /-ˈkʌvɚ/
(a.)祕密從事的,祕密的,被雇間諜活動的
undercover
adj : conducted with or marked by hidden aims or methods;
"clandestine intelligence operations";
"cloak-and-dagger activities behind enemy lines";
"hole-and-corner intrigue"; "secret missions"; "a
secret agent"; "secret sales of arms"; "surreptitious
mobilization of troops"; "an undercover investigation";
"underground resistance" [syn: clandestine, cloak-and-dagger,
hole-and-corner(a), hugger-mugger, hush-hush, on
the quiet(p), secret, surreptitious, underground]