/ Dictionary / Index P puerilism: Meaning and Definition of Find definitions for: pu•er•il•ism Pronunciation: (py'ur-u-liz"um, pyoor'u-), [key] — n. Psychiatry. childishness in the behavior of an adult. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. puerile puerility Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language