口無遮攔 [－无－拦]

Jyutping hau2 mou4 ze1 laan4
Pinyin kǒu wú zhē lán

Definitions (CC-CEDICT)
  1. to blab
  2. to shoot one's mouth off
  3. to commit a gaffe
Definitions (Wiktionary)
  1. phrase, idiomatic
    to have no misgivings or control when one speaks; to shoot one's mouth off
    (syn.) 口没遮拦, 口沒遮攔
Definitions (兩岸三地生活差異詞語彙編—Two Shores Three Places)
  1. 日常用語：臺
    口無遮攔
  2. 日常用語：陸
    沒下巴