from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An instrument used to make spectroheliograms.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. an instrument that produced monochromatic photographs of the sun using light at a selected wavelength
from the GNU version of the Collaborative International Dictionary of English
- n. An apparatus for making spectroheliograms, consisting of a spectroscopic camera used in combination with a telescope, and provided with clockwork for moving the sun's image across the slit.
from The Century Dictionary and Cyclopedia
- n. A specialized spectrograph, invented independently by Hale in the United States and by Deslandres in Paris about 1892, for the purpose of photographing the sun by monochromatic light.
spectro- + heliograph (Wiktionary)