- precocious - characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude); "a precocious child"; "a precocious achievement"
Antonyms: retarded, backward, feebleminded, dim-witted, half-witted, simple, simple-minded, cretinous, delayed
- precocious - appearing or developing early; "precocious flowers appear before the leaves as in some species of magnolias"
Antonyms: late, later (indirect, via early)