Definition of stereogenic:
(adj) :
consisting of a central atom and four distinguishable ligands such that the interchange of any two leads to a stereoisomer
(adj) :
consisting of four non-coplanar atoms such that rotation about the central bond leads to a stereoisomer
(adj) :
consisting of a double bond with substituents which give rise to cis-trans isomerism
(adj) :
(chemistry, physics) describing a grouping of atoms in a molecule