precocious vs youngsome

precocious

adj
  • Characterized by exceptionally early development or maturity. 

  • Exhibiting advanced skills and aptitudes at an abnormally early age. 

youngsome

adj
  • Seemingly young in appearance, manner, or behaviour; youthful 

How often have the words precocious and youngsome occurred in a corpus of books? (source: Google Ngram Viewer )