How do you say mill in Latin?

There isn't one single perfect Latin word for "mill" because the meaning depends on the type of mill. You'd need to be more specific. Here are some possibilities:

* For a grain mill: `pistrinum` (this refers to a mill building or the process of milling grain) or `mola` (this refers to the millstone itself). `Molendinum` is also used, a more general term for mill.

* For a water mill: `molendinum aquaticum` (literally "water mill") is a good choice.

* For a textile mill: There isn't a single perfect equivalent. You might need a descriptive phrase like `officina textoria` ("weaving workshop") or something more specific depending on the type of textile processing done.

Therefore, the best translation requires knowing the *kind* of mill you're referring to.