Definition from Wiktionary, the free dictionary
- enPR: kəm-pŭl'shən
compulsion (plural compulsions)
- An irrational need to perform some action, often despite negative consequences.
- During the basketball game, I had a sudden compulsion to have a smoke.
- The use of authority, influence, or other power to force (compel) a person or persons to act.
- The lawful use of violence (i.e. by the administration).
Related terms 
irrational need to perform some action
use of power to force a person to act
lawful use of violence