WordReference Random House Unabridged Dictionary of American English © 2024emis′sion spec′trum, [Physics.]- Physicsthe spectrum formed by electromagnetic radiations emitted by a given source, characteristic of the source and the type of excitation inducing the radiations.
Collins Concise English Dictionary © HarperCollins Publishers::
emission spectrum n - the continuous spectrum or pattern of bright lines or bands seen when the electromagnetic radiation emitted by a substance is passed into a spectrometer. The spectrum is characteristic of the emitting substance and the type of excitation to which it is subjected