mid-15c., from M.Fr. puérilité, from L. puerilitatem (nom. puerilitas) "childishness," from puerilis "childish, boyish," from puer "child, boy," from PIE *pu- "small, little, young" (cf. Skt. putrah "son, boy," Avestan puthra- "son, child;" cf.
few).