I imagine this word should be of Indoeuropean origin, Eastern Slav words for a mill also contain m-l-n (e.g. melnitsa).

Modern English lost the "n" part, but it was present in Middle English, milne.

yes, it's "mlin" or "mlyn" in a number of Slavic languages, and I just looked up it's etymology in Serbian and the book says it comes from old slavic "mъlinъ" which they say comes from the Latin root "molinum"

And in Greek: μύλος. With latin characters: milos. So it seems the root of the word is the same...

and Italian "il mulino"... it all comes from Latin "molinum" for the mill (and "mola" for the grind stone used in mills)

The name of Thor's hammer "mjolnir" (as english speakers would see it) did not come through latin though, so the version of the word in germanic languages was inherited independently.

"Mjolnir" means something like "crusher" and the noun "mjol" (flour) means "having been ground up". For example, it can be combined as vetemjöl (wheat flour) or stenmjöl (ground stone or stone powder).

> the noun "mjol" (flour) means "having been ground up"

Ah - "mjol" as flour must be cognate with "meal". I hadn't previously associated meal with mills, but it makes sense.

Meal appears to be a cognate of Old Norse "mál" ("mål", "måltid" - meal, meal time - in modern Norwegian) rather than mjol. Compare also Mehl (flour) vs Mahl (meal) in German.

Both meanings exist in English - "stonemeal" or "oatmeal" for example.

As another data point: meal/flour is "Mehl" in German. Mehl/meal is milled in a Mühle/mill.

Flour was originally only the highest quality grade- the "flower"- of ground grain.

Yes, "molino" is just mill. Windmill would be "molino de viento" and watermill "molino de agua".

An in German - Mühle... in fact the English Mill is pretty close too!