Origin of diatessaronEcclesiastical Latin from Ecclesiastical Greek (Evangelion) dia tessar?n, literally , (Gospel) through four, title of Tatian's harmony of four Gospels (2d circa ) from Classical Greek dia, through + tessar?n, genitive of tessares, four from Indo-European base an unverified form kwetwer-, four
Origin of diatessaronMiddle English interval of a fourth from Latin diatessarōn made of four from Greek dia tessarōn out of four dia according to ; see dia- . tessarōn genitive of tessares four ; see kwetwer- in Indo-European roots.
(plural diatessarons or diatessara)
Latin, from Ancient Greek διά (dia, “through, across”) + τεσσάρων (tessarōn) (genitive plural of τέσσαρες (tessares, “four”)).