A black operation or black op is a covert or clandestine operation by a government agency, a military unit or a paramilitary organization; it can include activities by private companies or groups. Key features of a black operation are that it is secret and it is not attributable to the organization carrying it out.

noun. Often black ops . a secret mission or campaign carried out by a military, governmental, or other organization, typically one in which the organization conceals or denies its involvement: Some national intelligence agencies use black ops to undermine enemy governments.