1. Reactions of the body to forces of a deleterious nature, infections, and various abnormal states that tend to disturb its normal physiologic equilibrium (homeostasis).
2. In dentistry, the forces set up in teeth, their supporting structures, and structures restoring or replacing teeth as a result of the force of mastication.
3. The force or pressure applied or exerted between portions of a body or bodies, generally expressed in pounds per square inch.
4. In rheology, the force in a material transmitted per unit area to adjacent layers.
5. In psychiatry and psychology, the abnormal mental and emotional state in response to a physical or physiologic stressor.
6. Stressor, in the sense that psychological stress can be a stressor to a person physically and the physical stress of illness can also be a psychological stressor.
7. In endocrinology, state of threatened homeostasis in which stressors are the threatening forces and adaptive responses are the forces of the organism that reestablish homeostasis.
The definition information for stress is provided by Stedman's. You can search our medical dictionary here.