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laser

The definition of a laser is a tool that creates a strong light beam made of atoms and molecules in an excited energy state.

(noun)

An example of a laser is a tool for removing unwanted hairs.

See laser in Webster's New World College Dictionary

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noun

a device containing a substance the majority of whose atoms or molecules can be put into an excited energy state, allowing the substance to emit coherent light of a precise wavelength in an intense, narrow beam

Origin: l(ight) a(mplification by) s(timulated) e(mission of) r(adiation)

See laser in American Heritage Dictionary 4

noun

Any of several devices that emit highly amplified and coherent radiation of one or more discrete frequencies. One of the most common lasers makes use of atoms in a metastable energy state that, as they decay to a lower energy level, stimulate others to decay, resulting in a cascade of emitted radiation.

Origin:

Origin: l(ight) a(mplification by) s(timulated) e(mission of) r(adiation)

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