/ ˈleɪzə(r); NAmE / noun
a device that makes a very strong line of controlled light (= with rays that are parallel and of the same wavelength ) :
a laser beam
a laser navigation device
The bar codes on the products are read by lasers.
a laser show (= lasers used as entertainment)
She's had laser surgery on her eye.
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WORD ORIGIN
1960s: acronym from light amplification by stimulated emission of radiation , on the pattern of maser .