夜郎自大

Yèlángzìdà
  1. lit. Yelang thinks highly of itself (idiom)
  2. fig. foolish conceit

CEDICT

Homographs

夜郎自大 yèlángzìdà

Entry Composition

1 夜郎 Yèláng small barbarian kingdom in southern China during the Han dynasty
2 自大 zìdà arrogant