precocious

Etymology

From Latin praecox (“premature, precocious, ripe before time, early ripe”), from praecoquere (“to ripen beforehand, ripen fully, also boil beforehand”), from prae (“before”) + coquere (“to cook, boil, ripen”).

adj

1. Characterized by exceptionally early development or maturity.
   The precocious plant was already blooming flowers by day 4.
   Scotland’s most encouraging early source of an attacking threat was Andrew Robertson as the precocious left-back charged forward to good effect on a couple of occasions. November 14, 2014, Stephen Halliday, “Scotland 1-0 Republic of Ireland: Maloney the hero”, in The Scotsman
2. Exhibiting advanced skills and aptitudes at an abnormally early age.
   The precocious child began reading the newspaper at age four.
   Mary: Even though the sound of it is something quite atrocious / If you say it loud enough you'll always sound precocious. 1964, Sherman Brothers (lyrics and music), “Supercalifragilisticexpialidocious”, in Mary Poppins, Walt Disney