@flo I’m not talking about usage, either. I’m talking about definitions. Here’s a dictionary definition for you:
milk
1. A white liquid produced by the mammary glands of female mammals to nourish their young. From certain animals, especially cows, it is also called dairy milk and is a common food for humans as a beverage or used to produce various dairy products such as butter, cheese, and yogurt.
2. A white (or whitish) liquid obtained from a vegetable source such as almonds, coconuts, oats, rice, and/or soy beans. Also called non-dairy milk.
And here’s another dictionary definition:
milk
1 An opaque white fluid rich in fat and protein, secreted by female mammals for the nourishment of their young.
1.1 The milk from cows (or goats or sheep) as consumed by humans.
1.2 The white juice of certain plants.
1.3 A creamy-textured liquid with a particular ingredient or use.
Finally, here is an Oxford Dictionary blog post on the matter.
And for what it’s worth, I’ve known plenty of doctors, dietitians, and nutritionists. None of them take issue with the fact that almond milk is a kind of milk.