[m-schuetz]

Some other words that are sorely missing from dictionaries: "Warm water", "hot water", "cold water", "dirty water"

[manarth]

As an idiomatic expression, "Hot water" = "trouble".

Are there idiomatic expressions for warm/cold/dirty water, which mean something other than a literal adjective describing the temperature or condition of water?

[jolmg]

> hot water - n. a difficult or dangerous situation

https://www.merriam-webster.com/dictionary/hot%20water

> warm water - n. an ocean or sea not in the arctic or antarctic regions

https://www.merriam-webster.com/dictionary/warm%20water

> cold water - n. depreciation of something as being ill-advised, unwarranted, or worthless. e.g. threw cold water on our hopes

https://www.merriam-webster.com/dictionary/cold%20water

Seems that what makes sense to be in dictionaries is already there.

[epolanski]

> dirty water

Depending on the context you got sewage, slush, runoff, murk, waste etc.