The Collaborative International Dictionary
Haloscope
Haloscope \Ha"lo*scope\ (h[=a]"l[-o]*sk[=o]p), n. [Halo + -scope.] An instrument for exhibition or illustration of the phenomena of halos, parhelia, and the like.
Wiktionary
haloscope
n. An instrument for exhibition or illustration of the phenomenon of halos, parhelion, and the like.