ant·li·on or ant lion (?nt?l???n)n. Any of various insects of the family Myrmeleontidae, having large-jawed larvae that dig a conical crater in the sand to trap ants and other insects for food.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.ant? li`on or ant?li`on, n. any of several nocturnal insects of the family Myrmeleontidae, resembling a damselfly, which as a larva (doodlebug) preys upon ants and other insects at the bottom of a conical sand trap with only its mandibles exposed. [1805?15] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.