1. The presence of an infectious agent on a body surface; also on or in clothes, bedding, toys, surgical instruments or dressings, or other inanimate articles or substances including water, milk, and food, or that infectious agent itself.
2. In epidemiology, the situation that exists when a population being studied for one condition or factor also possesses other conditions or factors that modify results of the study.
3. Freudian term for a fusion and condensation of meanings of words, percepts, or motivations for behavior.
4. The presence of foreign material that adulterates or renders impure a material the composition of which is thereby degraded.
Stedman’s Medical Dictionary © Wolters Kluwer Health. All rights reserved.