childish Antonyms

adult mature technical wise adult female fully grown age-old older of age ageing serious sensible oldish parental patriarchal ripe ripened ritual ritualistic senior creaky timeworn no spring chicken of a certain age silver-haired time-honoured vaned agile enough up in years advanced in years over the hill fully fledged drop-kick long-standing moth-eaten adulting adultish adultlike geriatric full-fledged in one's prime olden elder dotard dateless compensate cobwebby clever classical ascetic