planning has 2 distinct synonyms spread across 1 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.
an act of formulating a program for a definite course of action
“the planning was more fun than the trip itself”
the act or process of drawing up plans or layouts for some project or enterprise
the cognitive process of thinking about what you will do in the event of something happening
“his planning for retirement was hindered by several uncertainties”
Synonyms, antonyms and the broader and narrower relations for planning come from Princeton University’s WordNet. Full sources and licences.