The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
terkw-
DEFINITION:
To twist. 1. Possible variant (metathesized) form *twerk-.a.queer, from Middle Low German dwer, oblique; b.thwart, from Old Norse thverr, transverse. Both a and b from Germanic *thwerh-, twisted, oblique. 2. Suffixed (causative) o-grade form *torkw-eyo-.torch, torment, torque1, torque2, torsade, torsion, tort, tortuous, torture, truss; contort, distort, extort, nasturtium, retort1, torticollis, from Latin torqure, to twist. (Pokorny terk- 1077.)