Breadcrumb Home > Dictionary > Index I ichneumon fly: Meaning and Definition of Find definitions for: ichneu'mon fly" Pronunciation: [key] any of numerous wasplike insects of the family Ichneumonidae, the larvae of which are parasitic on caterpillars and immature stages of other insects. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ichneumon ichno- ✖ Related Content Daily Word Quiz: triumphalism Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language