/ Dictionary / Index A arco: Meaning and Definition of Find definitions for: ar•co Pronunciation: (är'kō), [key] — adv. Music. (of the performance of a passage for stringed instruments) with the bow. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: arco (Thesaurus) arc light Arc of Lowitz Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language