- (n.) The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed or studied either as spread out on a screen, by direct vision, by photography or otherwise. See Illust. of Light, and Spectroscope.
- (n.) An apparition; a specter.
- (n.) A luminous appearance or an image seen after the eye has been exposed to an intense light or a strongly illuminated object. When the object is colored, the image appears of the complementary color, as a green image seen after viewing a red wafer lying on white paper. Called also ocular spectrum.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). spectrum. Retrieved September 20, 2026, from http://smartdefine.org/spectrum/definitions/2064618 |
| Chicago | Webster's. 2011. "spectrum" http://smartdefine.org/spectrum/definitions/2064618 (accessed September 20, 2026). |
| Harvard | Webster's 2011, spectrum, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/spectrum/definitions/2064618>. |
| MLA | Webster's. "spectrum" 28 May 2011. Web. 20 September 2026. <http://smartdefine.org/spectrum/definitions/2064618> |