discharge

Concise Oxford English Dictionary © 2008 Oxford University Press:
discharge

▶verb /dɪsˈtʃɑːdʒ/ 

• 1 officially allow (someone) to leave somewhere, especially hospital.

  ■ dismiss from a job.

  ■ release from the custody or restraint of the law.

• 2 emit or send out (a liquid, gas, or other substance).

  ■ Physics release or neutralize the electric charge of (an electric field, battery, etc.).

  ■ fire (a gun or missile).

  ■ unload (goods or passengers) from a ship.

• 3 do all that is required to fulfil (a responsibility) or perform (a duty).

  ■ release from a contract or obligation.

  ■ Law relieve (a bankrupt) of residual liability.

• 4 Law (of a judge or court) cancel (an order of a court).

▶noun /ˈdɪstʃɑːdʒ, dɪsˈtʃɑːdʒ/ 

• 1 the action of discharging.

• 2 a substance that has been discharged.

  ■ a flow of electricity through air or other gas, especially when accompanied by emission of light.

– derivatives
dischargeable adjective,
discharger noun.

– origin ME: from OFr. descharger, from late L. discarricare ‘unload’, from dis- (expressing reversal) + carricare (see charge).