A daydream is a visionary fantasy, especially one of happy, pleasant thoughts, hopes or ambitions, imagined as coming to pass, and experienced while awake. There are many types of daydreams, and there is no consistent definition amongst psychologists. The general public also uses the term for a broad variety of experiences. Research by Harvard psychologist Deirdre Barrett has found that people who experience vivid dream-like mental images reserve the word for these, whereas many other people refer to milder imagery, realistic future planning, review of past memories or just “spacing out”–i.e. one’s mind going relatively blank—when they talk about “daydreaming.” //wikipedia