the flash of light that accompanies an electric discharge in the atmosphere (or something resembling such a flash); can scintillate for a second or more
abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission of light
derived from experiment and observation rather than theory; "an empirical basis for an ethical theory"; "empirical laws"; "empirical data"; "an empirical treatment of a disease about which little is known"
a methodical examination or review of a condition or situation; "he made an audit of all the plants on his property"; "an energy efficiency audit"; "an email log audit"
attend academic courses without getting credit
examine carefully for accuracy with the intent of verification; "audit accounts and tax returns"