Definitions of suction:

• noun:   a force over an area produced by a pressure difference
• noun:   the act of sucking
• verb:   empty or clean (a body cavity) by the force of suction

  Example: "Suction the uterus in an abortion"

• verb:   remove or draw away by the force of suction

  Example: "The doctors had to suction the water from the patient's lungs"