Stuff, that really really hurts with W

• waterboarding

  Torture by simulated drowning, causes extreme pain

• whip
• Wounds

  Injuries to tissue, often very painful to have

• waxing

  Hair removal method, often sharply painful

• wound

  An injury to the body, often severely painful

• Whipping

  Repeated whipping is a classic form of torture

• Whiplash

  Neck injury from sudden motion, very painful

• weapons

  Weapons inflict serious wounds and suffering

• war

  Armed conflict brings huge physical and emotional pain

The words in the list Stuff, that really really hurts with W come from players of the word game City, Country, River.