libido

In Freudian psychology, the energy of the sex instinct, which is to be found even in a newborn child. The libido develops through a number of phases, described by Sigmund Freud in his theory of infantile sexuality. The source of the libido is the id.

The phases of the libido are identified by Freud as the oral stage, when a child tests everything by mouth, the anal stage, when the child gets satisfaction from control of its body, and the genital stage, when the libido becomes concentrated in the sex organs.

Loss of adult libido is seen in some diseases; see also impotence.

Freud extended his usage of the term as his ideas on instinct developed, but he never used it, as Carl Jung and several other psychologists did, outside the sexual context.