/ Dictionary / Index T thistle butterfly: Meaning and Definition of Find definitions for: this'tle but"terfly Pronunciation: [key] any nymphalid butterfly of the genus Vanessa, as the red admiral or painted lady. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thistle thistledown Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language