An exciting or extraordinary scene, exhibition, performance etc. / An embarrassing or unedifying scene or situation.

(analytical chemistry) An optical instrument for measuring the absorption of light by chemical substances; typically it will plot a graph of absorption versus wavelength or frequency, and the patterns produced are used to identify the substances present, and their internal structure.

Amazing or worthy of special notice. / (dated) Related to, or having the character of, a spectacle or entertainment. / Relating to spectacles, or glasses for the eyes.

A spectacular display. / (advertising) A pop-up (folded paper element) in material sent by postal mail.

(analytical chemistry) A device for analyzing the chemical composition of substances using the characteristic spectral lines produced by their interaction with X-rays.

One who watches an event; especially, an event held outdoors.

Of, or pertaining to, spectres; ghostly. / Of, or pertaining to, spectra; classified according to frequency or wavelength (of light etc)

(physics) An electronic device that displays the frequency spectrum of an electrical, optical or acoustic waveform.

The colours of the rainbow. / (physics) The distribution of colours produced when white light passes through a prism. / (astronomy, physics) The range of frequencies of visible light.

(physics) The entire range of wavelengths of all known electromagnetic radiations extending from gamma rays, to X-rays through visible light, infrared, to radio waves.