Juvenileness refers to the state of being youthful or childlike. Some synonyms for this word are adolescence, immaturity, youthfulness, juvenility, childhood, and puerility. These words all have similar meanings and can be used interchangeably depending on the context. Adolescence specifically refers to the teenage years, while immaturity suggests a lack of emotional or mental maturity. Youthfulness and juvenility represent the energy and vitality of childhood and early adulthood. Childhood and puerility both suggest a more innocent and carefree time. These synonyms can add variety and nuance to your writing and help you express different aspects of juvenileness.