What is the meaning of wrenching?

verb

• Twist or pull violently or suddenly, especially so as to remove (something) from that to which it is attached or from where it originates.
  • usage: "wrench a window off its hinges"; "wrench oneself free from somebody's grip"; "a deep sigh was wrenched from his chest"
  • synonyms: wrench, twist
• Make a sudden twisting motion.
  • synonyms: wrench
• Twist and compress, as if in pain or anguish.
  • usage: "Wring one's hand"
  • synonyms: wring, wrench
• Twist suddenly so as to sprain.
  • usage: "wrench one's ankle"; "The wrestler twisted his shoulder"; "the hikers sprained their ankles when they fell"; "I turned my ankle and couldn't walk for several days"
  • synonyms: twist, sprain, wrench, turn, wrick, rick

adjective

• Causing great physical or mental suffering.
  • usage: "a wrenching pain"
  • synonyms: racking