infantilism

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. an abnormal condition in which an older child or adult retains infantile characteristics
• Hypernyms:
abnormality, abnormalcy
• Hyponyms:
ateleiosis, ateliosis
2. infantile behavior in mature persons
• Hypernyms:
misbehavior, misbehaviour, misdeed