1. In psychoanalysis, one of three components of the psychic apparatus in the freudian structural framework, the other two being the ego and superego. It is completely in the unconscious realm, is unorganized, is the reservoir of psychic energy or libido, and is under the influence of the primary processes.
2. The total of all psychic energy available from the innate biologic hungers, appetites, bodily needs, drives, and impulses, in a newborn infant; through socialization this diffuse undirected energy becomes channeled in less egocentric and more socially responsive directions (development of the ego from the id).
Stedman’s Medical Dictionary © Wolters Kluwer Health. All rights reserved.