verb

• (electricity) To release (an accumulated charge).
  "GWR plans to use it on the Greenford branch in west London, making use of a fast charger at West Ealing that will charge the batteries in just three and a half minutes. This fast charger is essentially a battery installed at the lineside which is trickle-charged from the electricity grid. It can then discharge quickly into the train's batteries through charging rails and then start recharging itself while the train is running in service."
• To relieve of an office or employment; to send away from service; to dismiss.
• To relieve of an office or employment; to send away from service; to dismiss.
• (logic) To release (an auxiliary assumption) from the list of assumptions used in arguments, and return to the main argument.

noun

• The act of expelling or letting go.
  "care transition after discharge"
• The act of expelling or letting go.
  "career transition after discharge"
• The process of flowing out.
  "Near-synonyms: effluent, effluence (sometimes synonymous)"
• (electricity) The act of releasing an accumulated charge.