spectral line

noun

, Optics.

1. a line in a spectrum due to the absorption or emission of light at a discrete frequency.

spectral line

/ spĕk′trəl /

1. An isolated bright or dark line in a spectrograph produced by emission or absorption of light of a single wavelength, generally corresponding to a specific shift in the energy of an electron moving from one orbital to another.

Word History and Origins

Origin of spectral line¹

First recorded in 1865–70