hanging has 3 distinct synonyms spread across 2 of its 3 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
decoration that is hung (as a tapestry) on a wall or over a window
“the cold castle walls were covered with hangings”
a form of capital punishment; victim is suspended by the neck from a gallows or gibbet until dead
“in those days the hanging of criminals was a public entertainment”
the act of suspending something (hanging it from above so it moves freely)
“there was a small ceremony for the hanging of the portrait”
Synonyms, antonyms and the broader and narrower relations for hanging come from Princeton University’s WordNet. Full sources and licences.