To traumatize someone is to make them feel a severe, lasting sense of shock and hurt. Being in a bad car accident can traumatize anyone.
In medicine, to traumatize is to hurt or injure physically, but this verb is used more often in everyday speech to mean "harm psychologically or emotionally." War and violence traumatize many people around the world, and even something as seemingly harmless as a scary movie can traumatize a young child. Traumatize comes from trauma, "physical wound" in medical Latin and "a wound, hurt, or defeat" in Greek.