幼稚
ようち · youchi · JLPT N2 · noun
childish
🍼 幼 (young) + 稚 (young, immature) = two 'young' characters stacked, meaning infancy or childish
幼 means young or infant, and 稚 means immature or young. Together 幼稚 covers both the stage of infancy and behavior that is childish. In everyday speech it is usually negative, like 'infantile'.