臨天光瀨尿 [临－－濑－]

Jyutping lam4 tin1 gwong1 laai6 niu6
Pinyin lín tiān guāng lài niào

Definitions (CC-CANTO)
  1. wetting the bed close to sunrise; cannot persist till the end (slang)
Definitions (粵典–words.hk)
  1. 語句
    喺​就​嚟​成功​、​爭​啲​就​完成​嘅​時​候​先​犯​錯​、​失敗
    a last minute failure in an enterprise which seemed headed for success, literally "to wet oneself before dawn"