/ Dictionary / Index T tobacco hornworm: Meaning and Definition of Find definitions for: tobac'co horn'worm Pronunciation: [key] the larva of a hawk moth, Manduca sexta, having a hornlike structure at its posterior end and feeding on the leaves of tobacco and other plants of the nightshade family. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tobacco heart tobacco mosaic Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language