noun (n)

• lacking and evidencing lack of experience of life(noun.state)

  Synonym:
  callowness, jejuneness
  

  source: wordnet30
• the freshness and vitality characteristic of a young person(noun.attribute)

  Synonym:
  youth, youthfulness
  

  source: wordnet30
• Youthfulness; adolescence.(noun)

  source: webster1913