tween vs youngster

tween

noun
  • A child, especially a girl, in the age range between middle childhood and adolescence, normally between eight and thirteen years of age. 

  • An action of tweening (inserting frames for continuity); a sequence of frames generated by tweening. 

  • a number or age in the twenties (plural only), or a person of that age 

adj
  • Of or having to do with tweenagers. 

verb
  • To generate intermediate frames in an animated sequence so as to give the appearance of smooth movement. 

youngster

noun
  • A young person. 

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