Antonyms of noun juvenile

1 sense of juvenile

Sense 1
juvenile, juvenile person -- (a young person, not fully developed)
       Antonym of adult (Sense 1)
      => adult, grownup -- (a fully developed person from maturity onward)

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun juvenile

1 sense of juvenile

Sense 1
juvenile, juvenile person -- (a young person, not fully developed)
       => person, individual, someone, somebody, mortal, soul -- (a human being; "there was too much for one person to do")

Antonyms of adj juvenile

1 of 2 senses of juvenile

Sense 2
adolescent, jejune, juvenile, puerile -- (displaying or suggesting a lack of maturity; "adolescent insecurity"; "jejune responses to our problems"; "their behavior was juvenile"; "puerile jokes")

INDIRECT (VIA immature) -> mature -- (characteristic of maturity; "mature for her age")

Similarity of adj juvenile

2 senses of juvenile

Sense 1
juvenile -- (of or relating to or characteristic of or appropriate for children or young people; "juvenile diabetes"; "juvenile fashions")

Sense 2
adolescent, jejune, juvenile, puerile -- (displaying or suggesting a lack of maturity; "adolescent insecurity"; "jejune responses to our problems"; "their behavior was juvenile"; "puerile jokes")
       => immature (vs. mature) -- (characteristic of a lack of maturity; "immature behavior")