Antonyms of adj imbecilic

1 sense of imbecilic

Sense 1
imbecile, imbecilic, idiotic -- (having a mental age of three to seven years)

INDIRECT (VIA retarded) -> precocious -- (characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude); "a precocious child"; "a precocious achievement")

Similarity of adj imbecilic

1 sense of imbecilic

Sense 1
imbecile, imbecilic, idiotic -- (having a mental age of three to seven years)
       => retarded (vs. precocious) -- (relatively slow in mental or emotional or physical development; "providing a secure and sometimes happy life for the retarded")