Precocious

1. (a.) Ripe or mature before the proper or natural time; early or prematurely ripe or developed; as, precocious trees.

2. (a.) Developed more than is natural or usual at a given age; exceeding what is to be expected of one's years; too forward; -- used especially of mental forwardness; as, a precocious child; precocious talents.

Thesaurus Entries

a bit previous, advanced, ahead, bright, developed, early, far ahead, forward, gifted, half-baked, half-cocked, hasty, ill-considered, impulsive, intelligent, mature, not firm, overhasty, oversoon, precipitate, premature, previous, quick, rushed, smart, soon, too early, too soon, uncrystallized, unjelled, unmatured, unmeditated, unpremeditated, unprepared, unripe, untimely