n. 1. The projected spot or circle of light used to illuminate brilliantly a single person or object or group on the stage, leaving the rest of the stage more or less unilluminated. [ Webster 1913 Suppl. ]
2. hence, conspicuous public notice. [ Cant or Colloq. ] [ Webster 1913 Suppl. ]
3. A lighting apparatus designed to throw an intense beam of light onto a small area. [ PJC ]