滚瓜烂熟 gǔn guā làn shú

DEFINITIONS

  1. lit. ripe as a melon that rolls from its vine (idiom); fig. to know fluently
  2. to know sth inside out
  3. to know sth by heart

CHARACTERS

滚 gǔn turn
瓜 guā melon, gourd, cucumber; rad. 97
烂 làn rotten, spoiled, decayed
熟 shú well-cooked; ripe; familiar with