sinsear Definitions (by source) Show all An Teagasg Críosdaidhe ai. sinsir, (our) first parents, 730; gi. sinsear 288. An Teagasg Críosdaidhe. Author: Bonabhentura Ó hEodhasa, O.F.M.. Editor: Fearghal Mac Raghnaill, O.F.M.