levogyrate

from The Century Dictionary.

• Causing to turn toward the left hand: as, a levogyrate crystal—that is, one that turns the rays to the right in the polarization of light. See dextrogyrate.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Chem., Physics, Biochem.) Turning or twisting the plane of polarization of light towards the left, as levulose, levotartaric acid, etc.; levorotatory.

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

• adjective chemistry, physics Turning or twisting the plane of polarization towards the left, as in levulose, levotartaric acid, etc.