Is it ensure, insure, or assure?
mechanism mech·a·nism (měk'ə-nĭz'əm)
A machine or mechanical appliance.
The arrangement of connected parts in a machine.
A system of parts that operate or interact like those of a machine.
An instrument or a process by which something is done or comes into being.
The involuntary and consistent response of an organism to a given stimulus.
A usually unconscious mental and emotional pattern that dominates behavior in a given situation or environment.
The sequence of steps in a chemical reaction.
The philosophical doctrine that all natural phenomena are explicable by material causes and mechanical principles.