What does laser mean?
A laser is a device that produces a narrow, highly directional beam of coherent light. Its name abbreviates the physical process involved: light amplification by stimulated emission of radiation. Lasers are used in medicine for delicate surgery and diagnosis, in manufacturing for precise cutting and engraving, in communications and measurement systems, and in everyday devices such as printers and disc readers. They also appear in military and scientific applications, where a precisely directed beam can illuminate, guide, or track a target. As a verb, to laser can mean directing a laser beam at something or treating it with laser light; in informal use, it can also mean to overwhelm an opponent decisively. The word is familiar in both British and American English. Its combination of technical precision and broad everyday use reflects the laser's distinctive status: it began as a highly specialized scientific instrument but became a common feature of medicine, industry, research, and consumer technology.
A device that generates a narrow, highly directional beam of coherent light through stimulated emission of radiation.
"The engineer adjusted the laser so that it focused precisely on the target."
The word is fully standard in technical and general English. It may refer to the device itself or, especially in military and scientific contexts, to the beam it produces.
To aim, direct, or track a target with a laser beam; to cut, alter, or treat something with laser light; or, informally, to defeat or overwhelm decisively.
"The aircraft was lased by the defensive system before it could approach."
The targeting, treatment, and overwhelming senses have different levels of formality; the last is chiefly informal.
The standard plural adds -s and is used for individual devices or, collectively, for multiple units in a system.
"The factory replaced several of its older lasers with newer models."
LASER stands for Light Amplification by Stimulated Emission of Radiation, giving one of science's most famous machines a name that reads like a formula.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does laser come from?
The noun laser was coined in the late 1950s as an acronym for Light Amplification by Stimulated Emission of Radiation. Its final element, radiation, belongs to a word family ultimately derived from Latin radix, meaning “root,” represented here by words such as radiate, radiant, and radiation. The verb lase was subsequently formed by back-formation from laser and developed specialized meanings involving laser light and laser treatment.
Related word forms
How laser is actually used
As a noun, laser is standard in technical, scientific, medical, and consumer contexts. As a verb, its targeting and treatment uses are established in specialist language, while the sense meaning to overwhelm is chiefly informal.
Easily confused with laser
A laser produces highly directional visible or infrared light, whereas a maser produces coherent microwave or radio radiation.