| 例句 |
undercoversnounpl. of undercover a person who tries secretly to obtain information for one country in the territory of another usually unfriendly countrywithin the city was a well-organized fifth column, and these undercovers would make themselves known as soon as the invading forces breached the city limits agents, assets, emissaries, intelligencers, moles, operatives, spies, spooks courierscounterspies, double agents, sleepersinfiltrators, informers, stool pigeonsspymasters, superspies secret agents, undercover agents |