Elmo

in St. Elmo's Fire "corposant," name given by seamen to the brushes and jets of electric light seen on the tips of masts and yard-arms, especially in storms, 1560s, from Italian fuoco di Sant'Elmo, named for the patron saint of Mediterranean sailors, a corruption of the name of St. Erasmus, an Italian bishop said to have been martyred in 303 who was invoked in the Mediterranean by sailors during storms.