盤根錯節 [盘－错节]

Jyutping pun4 gan1 co3 zit3
Pinyin pán gēn cuò jié

Definitions (CC-CEDICT)
  1. twisted roots and intertwined joints (idiom); complicated and very tricky
  2. knotty and deeply-rooted difficulties
Definitions (粵典–words.hk)
  1. x
Definitions (Wiktionary)
  1. phrase, idiomatic
    great tangled root system; complicated affair; complicated and difficult to deal with