maturation has 9 distinct synonyms spread across 3 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.
(biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level
“he proposed an indicator of osseous development in children”
(medicine) the formation of morbific matter in an abscess or a vesicle and the discharge of pus
Synonyms, antonyms and the broader and narrower relations for maturation come from Princeton University’s WordNet. Full sources and licences.