投井下石 [－－－－]

Jyutping tau4 zeng2 haa6 sek6
Pinyin tóu jǐng xià shí

Definitions (CC-CEDICT)
  1. to throw stones at sb who has fallen down a well (idiom)
  2. to hit a person when he's down
Definitions (Wiktionary)
  1. phrase, idiomatic
    Synonym of 落井下石 (luòjǐngxiàshí, “to kick someone when they are down”).
    (syn.) 落井下石