Meaning of LASER in English

/lay"zeuhr/ , n. Physics.

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. Also called optical maser .

[ 1955-60; l ( ightwave ) a ( mplification by ) s ( timulated ) e ( mission of ) r ( adiation ) ]

Random House Webster's Unabridged English dictionary.      Полный английский словарь Вебстер - Random House .