不露聲色 [－－声－]

Jyutping bat1 lou6 sing1 sik1
Pinyin bù lù shēng sè

Definitions (CC-CEDICT)
  1. not show one's feeling or intentions
Definitions (Wiktionary)
  1. phrase, idiomatic
    to maintain one's composure; to stay calm and collected; to not turn a hair; to not bat an eyelid; to not show or betray one's feelings or intentions
    (syn.) 不动声色, 不動聲色