/ Dictionary / Index C Canada thistle: Meaning and Definition of Find definitions for: Can'ada this'tle Pronunciation: [key] an Old World plant, Cirsium arvense, having small purple or white flower heads, now a troublesome weed in North America. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Canada moonseed Canada turpentine Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language