<p><strong>Noun:</strong></p><ul><li>An optical device for measuring wavelengths, deviation of refracted rays, and angles between faces of a prism.</li><li>Especially an instrument prism spectrometer consisting of:<ul><li>A slit through which light passes.</li><li>A collimator.</li><li>A prism that deviates the light.</li><li>A telescope through which the deviated light is viewed and examined.</li></ul></li></ul>