n. [ acronym from Light Amplification by Stimulated Emission of Radiation: ca. 1955. ] A device which produces an intense, usually narrow, monochromatic beam of coherent light; called also optical maser. It has various forms, and is used in various applications in science and technology. The beam is produced by boosting the majority of the electrons in specific radiation-absorbing atoms in a medium into a higher energy level, from which they are stimulated by their own emitted radiation to drop back synchronously to their lower energy level, and emit light which is in phase (coherent).
Syn. -- optical maser. [ WordNet 1.5 ]

n. A beam of light from a laser. [ PJC ]

n. A digital data storage medium consisting of a thin disk onto which the data is impressed by a laser, in the form of a linear sequence of dots; same as optical disk. The data is subsequently read back by the use of a laser beam. See also compact disk. The original disk may be created by use of a laser, but copies of the original disk may be created by a replicating process which does not itself require a laser. [ PJC ]

n. Light produced by a laser. [ PJC ]

n. A printer controlled by a computer, using a laser beam to produce images in a fine dot-matrix pattern of charge on an electrostatic drum, to which fine particles of ink are subsequently caused to adhere, and the image of which is subsequently transferred to paper or another type of material in sheet form. It is capable of high-speed production of images with a higher resolution than those from dot-matrix impact printers. [ PJC ]

n. (Med.) Surgery using lasers. [ PJC ]

n. [ L. laser the juice of the laserwort. ] (Bot.) Any plant of the umbelliferous genus Laserpitium, of several species (as Laserpitium glabrum, and Laserpitium siler), the root of which yields a resinous substance of a bitter taste. The genus is mostly European. [ 1913 Webster ]