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 . 2012