also: でいすい
noun
Literally water mixed with mud or dirt; also used figuratively for a difficult or morally impure situation.
雨のあと、川は泥水で濁っていた。
After the rain, the river was muddy and brown.
彼は泥水をすするような苦労をしてきた。
He has endured hardships as if drinking muddy water.
noun
Only with reading どろみず
Figurative use, likening the morally murky world of the pleasure quarters to muddy water. Often in the phrase 泥水稼業 (どろみずかぎょう).
彼女は泥水稼業から足を洗った。
She left the red-light district trade behind.
濁り水 also means muddy or turbid water, but is more neutral and descriptive, while 泥水 often carries a stronger nuance of dirt or moral impurity.
Compound of 泥 (mud) and 水 (water). The figurative sense for red-light district comes from the idea of a morally muddy or impure world.