/ Dictionary / Index M milkweed bug: Meaning and Definition of Find definitions for: milk'weed bug" Pronunciation: [key] any of several red and black lygaeid bugs, as Oncopeltus fasciatus, that feed on the juice of the milkweed. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. milkweed beetle milkweed butterfly Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language