puer·il·ism 
(pyrə-lĭz′əm, pwĕrə-, pyər-ə-)
(pyrə-lĭz′əm, pwĕrə-, pyər-ə-)n.
Childish behavior in an adult, especially as a symptom of mental illness.
- anti-Semite
- anti-Semitic
- anti-Semitism
- antisemitism
- antisense
- antisepsis
- antiseptic
- antiseptically
- antiserum
- antiskate
- antiskating
- antismog
- antismoking
- antisocial
- antisocially
- antisocial personality disorder
- antispasmodic
- antistat
- antistatic
- Antisthenes
- antistrophe
- antistrophic
- antistrophically
- antisubmarine
- anti-sway bar