1 A dark shape cast on a surface by an object blocking rays of light; more generally, an area of relative darkness.
2 In analytical psychology, the negative side of a person's personality, comprising all personal and collective elements that do not fit in with the person's self-perception and that are therefore denied overt expression but exist in the unconscious as an archetype (2). It is so called because it is the dark side of one's personality and is interpreted as a shadow cast by the ego. Carl Gustav Jung (1875–1961) described the shadow in a key passage as ‘that hidden, repressed, for the most part inferior and guilt-laden personality whose ultimate ramifications reach back into the realm of our animal ancestors and so comprise the whole historical aspect of the unconscious’ (Collected Works, 9, part 2, paragraph 422).
