- 贻害无穷 yíhàiwúqióng to have endless disastrous consequencesto leave behind a trail of trouble that never ends; to have long-lasting and severe negative consequences; also written as [[贻患无穷|貽患無窮|yi2 huan4 wu2 qiong2]]
- 养痈贻害 yǎngyōngyíhài neglect creates disasterto nurture a carbuncle and bequeath trouble; to leave an evil unchecked and thereby create future ruin