from the GNU version of the Collaborative International Dictionary of English
- n. A tracing or chart showing the phenomena attendant on thunderstorms.
- n. An instrument for making such tracings, as a recording brontometer.
from The Century Dictionary and Cyclopedia
- n. Same as brontometer.
- n. An apparatus devised by Marvin (1899) for recording any wave of sound, as thunder or the discharge of a cannon.
- n. A map or diagram showing the progress of the front of a thunder-storm by means of isobronts or equivalent lines for successive hours.
Sorry, no etymologies found.