flying dragonn. See flying lizard.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.fly?ing drag?on n. any arboreal lizard of the genus Draco, having an extensible membrane between elongated ribs for long, gliding leaps. Also called flying lizard. [1885?90] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.