To give light to; light up.To light up profusely; decorate with many lights, as for festivity, triumph, or homage: as, to illuminate one's house and grounds; the city was illuminated in honor of the victory.To enlighten; inform; impart intellectual or moral light to.To throw light upon; make luminous or clear; illustrate or elucidate.To decorate in color by hand; adorn with pictures, ornamental letters, designs, etc., in colors, gold, silver, etc., in flat tints, especially without shading, or with merely conventional shading: as, the illuminated missals or manuscripts of the middle ages.To display a profusion of lights, in order to express joy, triumph, etc.Enlightened; illuminated.Decorated with or as with colored pictures.n. One who makes pretension to extraordinary light and knowledge. See illuminati.