juvenility

juvenile +‎ -ity, from Latin iuvenilitas

juvenility (countable and uncountable, plural juvenilities)

1. The state or quality of being juvenile.
   • 1891, Thomas Hardy, Tess of the d'Urbervilles, volume 1, London: James R. Osgood, McIlvaine and Co., page 37:

     Next in juvenility to Abraham came two more girls, Hope and Modesty; then a boy of three, and then the baby, who had just completed his first year.

   The plant grew from juvenility to maturity in a week.

2. juvenile behaviour, writing, etc.
   • 1828, The Eclectic Review (volume 1, page 574)

     The frantic fanaticism of this paragraph deprives us of all hope that Mr. Irving will, as we once fondly hoped, outgrow his juvenilities.

• senility