prepare has 16 distinct synonyms spread across 6 of its 8 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.
create by training and teaching
“The old master is training world-class violinists”
lead up to and soften by sounding the dissonant note in it as a consonant note in the preceding chord
“prepare the discord in bar 139”
undergo training or instruction in preparation for a particular role, function, or profession
“She is training to be a teacher”
Synonyms, antonyms and the broader and narrower relations for prepare come from Princeton University’s WordNet. Full sources and licences.