洗底 [－－]

Jyutping sai2 dai2
Pinyin xǐ dǐ

Definitions (CC-CANTO)
  1. gangster giving up his membership or background; turn a new leaf
Definitions (粵典–words.hk)
  1. 動詞
    清洗​底細​；​掩蓋​、​消除​以往​嘅​履​歷​、​身份​。
    to clear one's identity or background (of certain misdeeds in the past)
    • 阿松佢喺度洗緊底，想其他人唔記得佢以前賣過白粉。
      阿松佢喺度洗紧底，想其他人唔记得佢以前卖过白粉。
      A-chung is trying to clear his background and make other forget that he once sold heroine.
Definitions (Wiktionary)
  1. verb
    to purge someone of their infamous or scandalous past