discharge has 38 distinct synonyms spread across 17 of its 20 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are charge, enlist.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
release from military service
become empty or void of its content
“The room emptied”
any of several bodily processes by which substances go out of the body
“the discharge of pus”
electrical conduction through a gas in an applied electric field
the termination of someone's employment (leaving them free to depart)
a formal written statement of relinquishment
Synonyms, antonyms and the broader and narrower relations for discharge come from Princeton University’s WordNet. Full sources and licences.