(of a person or their activities) involved in or involving secret work within a community or organization, especially for the purposes of police investigation or espionage (尤指警方调查或间谍)秘密工作的 an undercover police operation. 秘密警察行动。
provided with shelter 有覆盖物的;有外套的 undercover seating. 有外套座。
adverb
as an undercover agent 任密探(或特工) he worked undercover in Northern Ireland. 他在北爱尔兰从事密探工作。