遗害无穷

to have disastrous consequences / also written 貽害無窮|贻害无穷[yi2 hai4 wu2 qiong2]

to lose / to leave behind / to omit / to bequeath / sth lost / involuntary discharge (of urine etc)

(bound form) to leave behind

to do harm to / to cause trouble to / harm / evil / calamity

not to have / no / none / not / to lack / un- / -less

endless / boundless / inexhaustible

poor / destitute / to use up / to exhaust / thoroughly / extremely / (coll.) persistently and pointlessly