precocious \pri-KOH-shus\ (adjective) - 1 : Characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude); as, "a precocious child"; "a precocious achievement." 2 : (Botany) Flowering or fruiting early.
"Henry was precocious. His parents had great hopes for their offspring, and Henry, because he was so bright, seemed set apart for great things." -- Mary V. Dearborn, 'The Happiest Man Alive'
Precocious is from Latin praecox, praecocis, ripe before the time, premature, cooked beforehand, from praecoquo, praecoquere, to cook in advance, from prae-, before + coquo, coquere, to cook, to ripen.