puerile adj.

late 15c., puerilite, "a childish or silly act or expression," from Old French puérilité (15c.), from Latin puerilitatem (nominative puerilitas) "childishness," from puerilis "boyish, youthful; childish, trivial, silly," from puer "child, boy" (from PIE root *pau- (1) "few, little," with sense extended to "small, young;" source also of Latin putus "boy," Sanskrit putrah "son, boy," Avestan puthra- "son, child"). Meaning "puerile character or condition, boyishness" is by 1570s.

Proto-Indo-European root meaning "few, little."

It forms all or part of: catchpoll; encyclopedia; filly; foal; few; hypnopedia; impoverish; orthopedic; Paedophryne; paraffin; parvi-; parvovirus; paucity; Paul; pauper; pedagogue; pederasty; pedo-; pedophilia; poco; poltroon; pony; pool (n.2) "game similar to billiards;" poor; poulterer; poultry; poverty; puericulture; puerile; puerility; puerperal; pullet; pullulate; Punch; Punchinello; pupa; pupil (n.1) "student;" pupil (n.2) "center of the eye;" puppet; pusillanimous; putti.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit potah "a young animal," putrah "son;" Avestan puthra- "son, child;" Greek pauros "few, little," pais (genitive paidos) "child," pōlos "foal;" Latin paucus "few, little," paullus "little," parvus "little, small," pauper "poor," puer "child, boy," pullus "young animal;" Oscan puklu "child;" Old English feawe "not many, a small number," fola "young horse;" Old Norse fylja "young female horse;" Old Church Slavonic puta "bird;" Lithuanian putytis "young animal, young bird;" Albanian pele "mare."

also raja, "king or prince in India," ruling either independently or as a feudatory, 1550s, from Hindi, from Sanskrit rajan "king," related to raj "kingdom, kingship," rajati "he rules," and cognate with Latin rex, Old Irish rig "king" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule"). Related: Rajput, "member of the ruling caste in northern India" (1590s), from Sanskrit rajaputrah "prince," literally "king's son," from putrah "son, boy" (see puerile).