levorotatory

adjective

le·​vo·​ro·​ta·​to·​ry ˌlē-və-ˈrō-tə-ˌtȯr-ē 

: turning toward the left or counterclockwise

specifically : rotating the plane of polarization of light to the left compare dextrorotatory

Word History

First Known Use

1864, in the meaning defined above

Medical Definition

levorotatory

adjective

le·​vo·​ro·​ta·​to·​ry -ˈrōt-ə-ˌtōr-ē, -ˌtȯr- 

variants or levorotary

-ˈrōt-ə-rē 

or British laevorotatory or laevorotary

: turning toward the left or counterclockwise

especially : rotating the plane of polarization of light to the left compare dextrorotatory