Donatus (d???n??t?s) n1. (Biography) Aelius (?i?l??s). 4th century ad, Latin grammarian, who taught Saint Jerome; his textbook Ars Grammatica was used throughout the Middle Ages2. (Biography) 4th century ad, bishop of Carthage; leader of the Donatists, a heretical Christian sect originating in N Africa in 311 adCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014