The adjective precocious means displaying mental development at an early age, especially a child who is very clever, mature, or excellent at something.
Synonyms are bright, cocky, intelligent, or advanced.
The word origins from Latin (1640s) praecox (genitive praecocis) meaning “maturing early”. It comes from prae meaning “before” plus coquere meaning “to ripen”, literally “to cook”. It is originally used in relation with flowers or fruits. The figurative use, of persons, dates back to the 1670s.
He was a precocious child, with an early passion for music and art.
I never saw a driver as young as him, he’s a little precocious.
She was a precocious girl – learning the piano at three and playing the guitar at four.