Antonyms of adj senile

1 sense of senile

Sense 1
doddering, doddery, gaga, senile -- (mentally or physically infirm with age; "his mother was doddering and frail")

INDIRECT (VIA old) -> young, immature -- ((used of living things especially persons) in an early period of life or development or growth; "young people")

Similarity of adj senile

1 sense of senile

Sense 1
doddering, doddery, gaga, senile -- (mentally or physically infirm with age; "his mother was doddering and frail")
       => old (vs. young) -- ((used especially of persons) having lived for a relatively long time or attained a specific age; "his mother is very old"; "a ripe old age"; "how old are you?")