자신의 진짜 정체나 목적을 숨기고 비밀리에 조사나 첩보 활동을 수행하는
Working secretly or in disguise, especially to investigate crimes or gather private information
예문:
"The detective spent six months undercover to gather evidence against the gang."
"An undercover investigation revealed that the company was dumping toxic waste."
"She wore an undercover wire to record the conversation secretly."