釘牀 [钉床]

Jyutping deng1 cong4
Pinyin dīng chuáng

Definitions (粵典–words.hk)
  1. 名詞
    鋪滿​釘​嘅​板​，​畀​人​瞓​上去​，​用​嚟​表演​（​量​詞​：​張​）
    bed of nails