er·y·throl \ˈerəˌthrȯl, ə̇ˈriˌth-, -ōl\noun (-s) Etymology: International Scientific Vocabulary erythr- + -ol 1.: a liquid unsaturated dihydroxy alcohol CH2 = CHCHOHCH2OH formed by decomposition of erythritol 2.: erythritol — used especially in pharmacy < erythrol tetranitrate >