noun.
An irresistible impulse to act, regardless of the rationality of the motivation.
noun.
An act or acts performed in response to such an impulse.
The Century Dictionary and Cyclopedia
noun.
The application (to a person) of superior force, physical or moral, overpowering or overruling his preferences; the force applied; constraint, physical or moral.
the GNU version of the Collaborative International Dictionary of English
noun.
The act of compelling, or the state of being compelled; the act of driving or urging by force or by physical or moral constraint; subjection to force.