geometric isomer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A chemical compound having the same molecular formula as another but a different geometric configuration, as when atoms or groups of atoms are attached in different spatial arrangements on either side of a bond or a ring.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun chemistry either the cis- or trans- isomer of a compound that exhibits geometric isomerism