IPA: /prɪˈkoʊʃnəs/
KK: /prɪˈkoʊʃnəs/
The state of developing abilities or talents at an earlier age than usual.
Her precociousness in mathematics impressed her teachers and classmates alike.
Precociousness → It is formed from "praecoquere" (meaning to ripen or cook beforehand) and the suffix "-ness" (meaning the state or quality of). The word "precociousness" refers to the state of being unusually advanced or mature at an early age, as if having ripened early.
Think of someone who is 'ripening' ('praecoquere') early in their abilities or talents, which helps you remember that 'precociousness' means being advanced for one's age.