/ Dictionary / Index A arca: Meaning and Definition of Find definitions for: ar•ca Pronunciation: (är'ku), [key] — pl. -cae a chest for valuables, used in medieval Spain and Italy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: arca (Thesaurus) arc arcade Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language