undercover

undercover — 形容詞

1. describes a person — such as a police officer, agent, or journalist — who works

1.形容詞B2
釋義

臥底的

使用假身份秘密調查的

describes a person — such as a police officer, agent, or journalist — who works using a false name, appearance, and personal history in order to secretly gather information about criminal or suspicious activity.

例句

Saira posed as a journalist during a three-year undercover investigation of a drug network.

Saira 以記者身分進行了為期三年的臥底調查，目標是一個販毒網絡。

attributive: undercover investigation

The detective's undercover work led to the arrest of seven corrupt officials.

這位警探的臥底工作導致七名貪腐官員被捕。

possessive + undercover + noun (work)

同義詞
  • covert

    broader in scope — describes any hidden operation, not necessarily involving a false identity

  • clandestine

    more dramatic, often implies secrecy for illegal purposes; less common in everyday news language

  • secret

    the most general term; does not specifically convey the idea of assuming a false identity

  • plainclothes

    limited to police officers who wear ordinary clothes instead of a uniform, but not necessarily using a false identity

反義詞
  • public

    open and known to everyone, the opposite of hidden

  • overt

    formal term meaning done openly, without concealment

文法句型

undercover + noun (role/investigation/unit)

用法筆記

This adjective nearly always appears immediately before the noun it describes. You cannot use it alone after a linking verb to describe a situation — for that meaning, use the adverb form (e.g. 'The agent worked undercover').

常見錯誤

❌The spy was undercover in the building' (using adjective predictively).
✅The spy worked undercover in the building
💡when the meaning is 'acting secretly,' use the adverb after a verb.
❌They ran an undercover' (missing noun after the adjective).
✅They ran an undercover operation.
💡undercover is always attached to a noun in its adjective form.

undercover — 副詞