Wiktionary
geometric isomerism
n. (context chemistry archaic deprecated by IUPAC English) A form of isomerism in which, in one isomer two atoms or groups are on the same side of the plane of a double bond or ring, whereas in the other isomer they are on opposite sides; these are cis- and trans- isomers, respectively.
Usage examples of "geometric isomerism".
Great balks of information flooded down the thick nerve cord to his nose, carrying inexplicable information about triple bonds, alkanes and geometric isomerism.