- a device that produces a nearly parallel, nearly monochromatic, and coherent beam of light by exciting atoms to a higher energy level and causing them to radiate their energy in phase.
- a source of high-intensity optical, infrared, or ultraviolet radiation produced as a result of stimulated emission maintained within a solid, liquid, or gaseous medium. The photons involved in the emission process all have the same energy and phase so that the laser beam is monochromatic and coherent, allowing it to be brought to a fine focus
- any similar source producing a beam of any electromagnetic radiation, such as infrared or microwave radiation
- to use a laser on (something), esp as part of medical treatment
- to remove (a tattoo, fat, etc) with laser treatment
- a type of dinghy, designed to be sailed by one person
