undercover

adj [esp attrib尤作定语] 1 doing things secretly or done secretly; surreptitious 暗中进行的; 秘密做出的; 私下的: ,undercover`payments, eg bribes 暗中付的款（如贿赂）. 2 engaged in spying on people while appearing to work normallyamong them 做密探工作的: ,undercover `agents, activities ,organizations 密探、 秘密活动、 进行秘密活动的组织 * detectives working undercover 掩人耳目行事的侦探.

under control, under the charge of, under the heel of, under the order of, under way, under-, under-secretary, under-sexed, under-side, underachieve, underachiever, underact, underarm, underbelly, underbid, underbrush, undercarriage, undercharge, underclothes, undercoat, undercurrent, undercut, underdeveloped, underdog, underdone, underestimate, underexpose, underexposure, underfed, underfelt, underfloor, underfoot, undergarment, undergird, undergo, undergraduate, underground, undergrowth, underhand, underhanded,