jacinthEnglishOxford Dictionary of Englishjacinth /ˈdʒasɪn(t)θ , ˈdʒeɪsɪn(t)θ / ▸ noun [mass noun] a reddish-orange gem variety of zircon. – ORIGIN Middle English: from Old French iacinte or medieval Latin iacintus, alteration of Latin hyacinthus (see hyacinth).