adult vs fledgling

adult

noun
  • A fully grown human or animal. 

  • A person who has reached the legal age of majority. 

adj
  • Containing situations or discussions intended primarily for adults, such as serious crime, illicit drug use, extramarital affairs, etc. 

  • Containing marijuana, intended for consumption only by adults. 

  • Fully grown. 

  • Containing material of an explicit sexual nature; of, or pertaining to, pornography. 

  • Containing excessive vulgar or profane speech, text or images, intended only for adults. 

  • Intended for or restricted to adults rather than children due to size, maturity, knowledge level, judgement, etc. 

  • Containing alcohol, intended for consumption only by adults. 

verb
  • To (cause to) be or become an adult. 

  • To behave like an adult. 

fledgling

noun
  • An insect that has just fledged, i.e. undergone its final moult to become an adult or imago. 

  • A young bird which has just developed its flight feathers (notably wings). 

  • An immature, naïve or inexperienced person. 

adj
  • Emergent or rising. 

  • Untried or inexperienced. 

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