a process in which individuals (or small groups) penetrate an area (especially the military penetration of enemy positions without detection)

avoiding detection by moving carefully

designed to elude detection, Not visible or apparent, verb_ Past participle of hide, past participle_ from hide Concealed; put out of view; secret; not known; mysterious

A person, usually a member of a police force, who investigates crimes and obtains evidence or information, an investigator engaged or employed in obtaining information not easily available to the public, One who business it is so detect criminals or discover matters of secrecy, adjective_ Fitted for, or skilled in, detecting; employed in detecting crime or criminals, Suited for or used in detection,