n. in psychoanalytic theory, the oral factor in eroticism or neurosis, ranging from pleasure in biting, sucking, smoking, or oral sex to such habits as speech-making, overeating, and alcoholism.
the phenomenon in which an object or its properties (e.g., size, shape, color) appear unchanged despite variations in the stimulus itself or in the external conditions of observation, such as object orientation or level of illumination. Examples of perceptual constancy include brightness constancy, color constancy, shape constancy, and size constancy.