Definitions of exhaust:

• noun:   system consisting of the parts of an engine through which burned gases or steam are discharged
• noun:   gases ejected from an engine as waste products
• verb:   use up the whole supply of

  Example: "We have exhausted the food supplies"

• verb:   wear out completely

  Example: "This kind of work exhausts me"

• verb:   deplete

  Example: "Exhaust one's savings"

• verb:   create a vacuum in (a bulb, flask, reaction vessel, etc.)
• verb:   use up (resources or materials)

  Example: "We exhausted our savings"