from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An unintended electric arc, as between two pieces of apparatus.
- n. The temperature point at which the heat in an area or region is high enough to ignite all flammable material simultaneously.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The near simultaneous ignition of all combustible material in an enclosed area.
- n. An unintended electric discharge or arc over or around an insulator
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an unintended electric discharge (as over or around an insulator)
flash + over (Wiktionary)