Definition of "puerile"

The French have been notorious through generations for their puerile affectation of Roman forms, models, and historic precedents.

1850, Thomas De Quincey, French and English Manners (originally published in Hogg's Instructor

From the table he had received the gout; from the alcove a tendency to convulsions; from the grandeeship a pride so vast and puerile that he seldom heard anything that was said to him and talked to the ceiling in a perpetual monologue; from the exile, oceans of boredom, a boredom so persuasive that it was like pain,—he woke up with it and spent the day with it, and it sat by his bed all night watching his sleep.

1927, Thornton Wilder, The Bridge of San Luis Rey, page 79

Society is undergoing a silent revolution, which must be submitted to, and which takes no more notice of the human existences it breaks down than an earthquake regards the houses it subverts. The classes and the races, too weak to master the new conditions of life, must give way. But can there be anything more puerile, more short-sighted, than the views of those Economists who believe in all earnest that this woeful transitory state means nothing but adapting society to the acquisitive propensities of capitalists, both landlords and money-lords?

1853 March 22, Karl Marx, “Forced Emigration”, in New-York Tribune‎

[…] I have always found it hard that Hamlet, a character that I love and admire, is guilty of a puerile misogyny and, perhaps, more worryingly, of the unnecessary deaths of his old friends from university, Rosencrantz and Guildenstern.

2014 April 12, Simon Russell Beale, “Why Shakespeare always says something new: As the 450th anniversary of Shakespeare's birth approaches, the great Shakespearean actor Simon Russell Beale explains his secrets [print version: The king and I]”, in The Daily Telegraph (Review)‎, London, page R7

Today we should welcome, and even study, every serious attempt to envisage the future of our race, not merely to grasp the very diverse and often tragic possibilities that confront us, but also that we may familiarize ourselves with the certainty that many of our cherished ideals would seem puerile to more developed minds.

1930 July, West Kirby, Last and First Men by Olaf Stapledon, Preface (page 9 of the Dover 1968 reprint of L&FM and Star Maker)