Paramilitary designates forces whose function and organization are similar to those of a professional military force, but which are not regarded as having the same status. The term uses the Greek/Latin prefix para- ("beside"), also seen in words such as paramedic. In some countries, the term may refer to official semi-militarized law enforcement, guard, or volunteer organizations. However, sometimes the term is used similarly to "irregular military" and may thus be used to label various completely non-official and even illegal organizations formed on a military pattern.
The term paramilitary is subjective, depending on what is considered similar to a military force, and what status a force is considered to have. The term may indicate an official or a semi-official status or a desire for such a status. Under the law of war, a state may incorporate a paramilitary organization or armed agency (such as a national police or a private volunteer militia) into its combatant armed forces. The other parties to a conflict have to be notified thereof.
The nature of paramilitary forces therefore varies greatly according to the speaker and the context. For instance, in Northern Ireland, paramilitary refers to any illegally armed group with a political purpose, but in Colombia, paramilitary refers specifically to illegally armed groups which are considered right-wing (e.g. AUC), while illegally armed groups considered left-wing, such as FARC, are referred to as guerrillas.
Depending on context, paramilitaries can include:
- Military forces outside the army, e.g. gendarmeries and forces such as the Indian Paramilitary Forces and People's Armed Police.
- Illegal forces which consider themselves military but which governments consider terrorist, e.g. Provisional IRA, Ulster Volunteer Force, AUC, guerrillas.
- Private armies and militias.
- Militarized preexisting government agencies, such as SWAT teams.
- Auxiliary services of regular armed forces, such as the United States Coast Guard Auxiliary and the adult portion of the Civil Air Patrol.
- Youth groups and movements that can be considered 'militarized' to various degrees. Modern examples include miltary cadet movements like the Royal Canadian Air Cadets, the American Civil Air Patrol and India's National Cadet Corps.