le|vo|ro|ta|to|ry

le|vo|ro|ta|to|ry «_LEE voh ROH tuh _TR ee, -_TOHR-», adjective.

1. turning or causing to turn toward the left or in a counterclockwise direction.

2. Chemistry, Physics. characterized by turning the plane of polarization of light to the left, as a crystal, lens, or compound in solution (contrasted with dextrorotatory). Also, laevorotatory.