emission

emis·sion

noun \ē-ˈmish-ən\

Definition of EMISSION

1

: an act or instance of emitting

2

a : something sent forth by emitting: as (1) : electrons discharged from a surface (2) : electromagnetic waves radiated by an antenna or a celestial body (3) : substances and especially pollutants discharged into the air (as by a smokestack or an automobile gasoline engine) b : a discharge of fluid from a living body; especially : ejaculate—see nocturnal emission