Libido in its common usage means sexual desire; however, more technical definitions, such as those found in the work of Carl Jung, are more general, referring to libido as the free creative—or psychic—energy an individual has to put toward personal development or individuation. History of the concept Sigmund Freud popularized the term and defined libido as the instinct energy or force, contained in what Freud called the id, the largely unconscious structure of the psyche. Freud po… (More on Libido)