It isn't cow milk, but other than that I'm not really sure what you're saying. Milk is what you get when milking an animal. It's a pretty broad term. However I do doubt that this would be as nutritious to humans as milk from cows or other mammals.
No, sometimes you get venom.
https://www.terminix.com/blog/science-nature/milking-spiders... https://www.youtube.com/watch?v=pIJ_sVwVhpQ
From the article: containing nearly four times the protein of cow’s milk
And we needn't get into how "coconut milk", "almond milk", etc. are somehow inappropriate uses of "milk" despite their entry into the lexicon millennia ago.
Not to mention the Milky Way.
Also keep in mind that it took humans some time of evolution to be able to digest cow milk.
All human babies have a much greater propensity to be able to digest lactose than adult humans.
Whey and casein are the dominant proteins, and lactose the dominant carbohydrate, in both human and cow milk.
Humans and cows aren’t that different. All mammals have quite a lot in common.
This is because most people produce some lactase it’s more a question on quantity of milk consumed.
Which is why almond, soy etc. would be called almond or soy drink in the EU you can’t even advertise it as a milk substitute.
This says people have been calling other things milk for at least 800 years and suggests the origination might be in the verb form rather than the noun form.
Also, defined by whom?
[0]https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mod...
> We suggest this milk might have evolved from trophic eggs, unviable eggs functioning as a food for newly emerged offspring