WordNet sense 1 (unbearable physical pain):

torment, torment

WordNet sense 2 (extreme mental distress):

anguish

WordNet sense 3 (intense feelings of suffering; acute mental or physical pain):

agony

WordNet sense 4 (torment emotionally or mentally):

rack, excruciate

WordNet sense 5 (the act of distorting something so it seems to mean something it was not intended to mean):

distortion, overrefinement, straining, twisting

WordNet sense 6 (the deliberate, systematic, or wanton infliction of physical or mental suffering by one or more persons in an attempt to force another person to yield information or to make a confession or for any other reason):

torturing