St. El?mo’s fire (??l mo?z) n. a form of luminous corona discharge that sometimes occurs during electrical storms. [1880?85; after St. Elmo (d. A.Dutch. 303), patron saint of sailors; compare Italian fuoco di Sant’Elmo] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.