/ Dictionary / Index A Arsaces I: Meaning and Definition of Find definitions for: Ar•sa•ces I Pronunciation: (är'su-sēz", är-sā'sēz), [key] founder of the Parthian empire c250 b.c. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ARS Ars Antiqua Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language