clandestine definition

Definition of clandestine : adjective

1. Illicit and hidden. A clandestine operation depends for its success upon not being detected, because if detected it would immediately be recognized for what it is. Landing a team of commandos from a submarine at 3:00 AM in the dark of the moon would be a clandestine operation. The Watergate burglary was a clandestine operation. Contrast covert.