The state, quality, or condition of being childish or puerile. / That which is puerile or childish; especially, an expression which is insipid or silly.

Childish; trifling; silly. / Characteristic of, or pertaining to, a boy or boys; compare puellile.

In a puerile manner; childishly.

The quality of being puerile; puerility.

plural of puerility

(psychology, psychiatry) Childlike behavior by an adult, especially as indicating a mental disorder.

plural of puerilism

(rare) The act or process of acquiring puerile characteristics.