/ Dictionary / Index A Arcturus: Meaning and Definition of Find definitions for: Arc•tu•rus Pronunciation: (ärk-toor'us, -tyoor'-), [key] — n. Astron. a first-magnitude star in the constellation Boötes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: arcturus (Thesaurus) arctophile arcuate Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language