eido-, eid-; ido-, id- +

(Greek: image, figure, form, shape; literally, "that which is seen")

kaleidoscope, kaleidoscopical
An optical instrument, consisting of from two to four reflecting surfaces placed in a tube, at one end of which is a small compartment containing pieces of colored glass: on looking through the tube, numerous reflections of these are seen, producing brightly-colored symmetrical figures, which may be constantly altered by rotation of the instrument.
kaleidoscopic (adjective), more kaleidoscopic, most kaleidoscopic
Descriptive of a device that exhibits brightly colored and continually varying figures.
An instrument invented by Prof. A. E. Dolbear (West Virginia), consisting of a tube closed at one end by a tense membrane, having attached to its center a small mirror, to show the musical vibration caused by speaking or singing at the open end.
phoneidoscope, phoneidoscopic
1. An instrument for exhibiting the color-figures produced by the action of sound-vibrations upon a thin film, e.g. of soap-solution.
2. An instrument for studying the motions of sounding bodies with optical methods.

Inter-related cross references, directly or indirectly, involving word units dealing with "form, shape, appearance": figur-; form-; icono-; ideo-; imag-; morpho-; -oid; typo-.