Lewis & Short

pŭĕrīlĭtas, ātis, f. [puerilis].

  1. I. Boyhood, childhood (ante- and post-class.), Varr. ap. Non. 494, 19; Val. Max. 5, 4, 2.
  2. * II. Childish conduct, childishness, puerility, Sen. Ep. 4, 2.