The science of the human soul; specifically, the systematic or scientific knowledge of the powers and functions of the human soul, so far as they are known by consciousness; a treatise on the human soul.
- The science that deals with mental processes and behavior.
- The emotional and behavioral characteristics of an individual, group, or activity: the psychology of war.
- Subtle tactical action or argument used to manipulate or influence another: He used poor psychology on his employer when trying to make the point.
- Philosophy The branch of metaphysics that studies the soul, the mind, and the relationship of life and mind to the functions of the body.