le·vo·ro·ta·to·ry (lēvə-rōtə-tôrē, -tōrē) also le·vo·ro·ta·ry (-tə-rē)
adj. Symbol l-
Of or relating to an optically active chemical that rotates the plane of polarized light to the left, or counterclockwise:
Only levorotatory amino acids are biologically active.

[TahlilGaran] American Dictionary ▲