one of the isomers of a compound that exhibits stereoisomerism
stereoisomer in American English
(ˌstɛrioʊˈaɪsəmər; ˌ stɪrioʊˈaɪsəmər)
noun
any of two or more isomers containing the same atoms linked in an identical manner in the molecule and differing from each other only in the spatial arrangement of the atoms or groups of atoms