From Longman Dictionary of Contemporary Englishsheet lightningˌsheet ˈlightning noun [uncountable] HEMa type of lightning that appears as a sudden flash of brightness covering a large area of sky → forked lightning
Examples from the Corpus
sheet lightning• They were all laughing and peering over and down, their heads black against sheet lightning.• Continuous sheet lightning made the use of a torch in the ten unnecessary.• Ronni jerked against him, feeling a sensation like sheet lightning root her to the spot. 