extortor

extorsion

 [eks-tor´shun]
tilting of the upper part of the vertical meridian of the eye away from the midline of the face.

ex·tor·tor

(eks-tōr'tor, -tōr),
An outward rotator.

extortor

/ex·tor·tor/ (eks-tor´ter)
1. an outward rotator.
2. an extraocular muscle that produces extorsion.