(n.) The state or quality of being childish; simplicity; harmlessness; weakness of intellect.

anility babyishness boylikeness caducity callowness childlikeness decline dotage dotardism girlishness immaturity imprudence inadvisability inattention inconsideration indiscreetness indiscretion inexpedience infantilism injudiciousness irrationality maidenliness pompousness puerilism puerility reasonlessness recklessness second childhood senectitude senile debility senile dementia senile psychosis senile weakness senilism senility senselessness stuffiness thoughtlessness unintelligence unreason unreasonableness unsensibleness unsoundness unthoughtfulness unwisdom unwiseness witlessness